Public health Flashcards
Traceability required for cattle, pigs, sheep and horses?
Cattle: 2 ear tags and passport
Pigs: slap marks/tattoos or ear tags, and movement licenses
Sheep: 1 ear tag required with flock/herd mark if <1yo, 2 ear tags if >1yo including electronic identification, and movement licenses
Horses: transponder and passport
What does Food Chain Information (FCI) include and who is responsible for obtaining and evaluating it?
Disease status
Knowledge of residues
Movement restrictions (TB or other)
More extensive in chickens
Food Business Operator (FBO) responsible for obtaining and evaluating the FCI
OV audits FBO’s decisions
FBO decides to accept, reject to apply corrective action based on this info
What are BSE passive and active surveillance ?
Active:
- emergency slaughter, AM changes (accidents or serious physiological and functional problems) in bovines >48mo if EU25, >24mo if non EU25 (doesn’t include clinical signs of BSE as in this case APHA would need to be notified)
- healthy in >30mo bovines if non EU25 (not done in EU25)
Passive:
- testing when potential cases are reported (suspicious clinical signs)
- clinical cases detected on farm and/or at AM inspection in the abattoir
- protocol same as any other notifiable disease ie notify VO etc
- brainstem (cattle) or brainstem and cerebellum (ovine/caprine) examined
Which sheep are tested as part of Scrapie active surveillance? What is tested?
Aged >18mo (>2 permanent incisors)
Sample of
- fallen goats/sheep
- healthy goats/sheep slaughtered in participating slaughterhouses
- fallen stock from compulsory scrapie flock schemes (CSFC)
Testing samples:
- brainstem
- cerebellum
- increased analytical sensitivity and atypical scrapie
When are compulsory scrapie flock schemes (CSFS) carried out? What does it involve?
Farms where positive cases identifies
Movement restrictions for 2 years
Sheep: genotyping of whole flock and slaughter of scrapie susceptible sheep or total flock slaughter with or without genotyping
Goats: whole flock slaughtered
Restocking with the more resistant genotypes
TSE surveillance for the 2 year period after CSFS measures have been enacted (all cull sheep and all fallen sheep >18mo at time of death)
Which pigs are tested for Trichinella for slaughter?
Breeding domestic swine (sows and boars)
Wild boar (any age)
Solipeds (any age)
All pigs that have not been reared in premises officially considered to apply controlled housing conditions
Exemption only applicable to domestic pigs: freezing treatment instead of testing
Controlled pig housing conditions for Trichinella?
Building construction and maintenance
Pest control programme and records
Feed provider
Storage of feed
Management of dead animals
Rubbish dump in the neighbourhood - inform and assessment of risk
Animal identification
Introduction of new animals from holdings officially recognised as applying controlled housing conditions
No access to outdoor facilities unless operator can show do not pose danger for intro of Trichinella
None of the swine for breeding and production, has been unloaded after leaving the holding of origin at an assembly centre unless meets the requirements and all originate in and come from holdings officially recognised as applying controlled
Sections of a horse passport?
Section I: owner/agent must be stated
Sections II and III: identification by the competent authority
Section IV: recording identity checks whenever laws and regulations so require
Section V and VI: all vaccinations must be recorded (equine influenza in section V and all others in section VI)
Section VII: laboratory health tests to detect transmissible diseases must be recorded
Section VIII: food chain information (FCI)
Section IX: medicinal treatment
Section IX part IIa: owner/representative declaration to stop animal from entering food chain
Vet surgeon responsible for transponder implanting and completion of sections V, VI, VII and IX (otherwise guilty of an offence)
Withdrawal periods for medicinal products for horses?
Allowed substances (table 1): specified per product Essential substances: 6 months
What can the FSA do if suspicion of residues at slaughter (authorised but above maximal residue limit, unauthorised substance, or prohibited substance)?
Detain animals for further examination
Sample tissues/fluids taken for analysis
Detain the animal/carcass or group of animals/carcases until results of the analysis are available
Signs of beta-agonist residues in live animals and PM? Sample collected?
Good conformation with little fat
Hyperaesthesia and tachycardia may be present
PM: flaccidity of the trachea
Urine collected
Signs of hormone growth promoter residues in live animals and PM? Samples collected?
Secondary sexual characteristics Teat development Restlessness behavioural changes Mounting Aggression An even level of finish in a group of cattle of different breed/types PM: injection sites - oily Blood and urine or faeces collected
When must the ante-mortem inspection by an OV be carried out at a slaughterhouse? What outcomes are there?
Within 24h of animal’s arrival at slaughterhouse and <24h prior to slaughter
Outcomes:
- Fit for slaughter
- Fit for slaughter under certain conditions
- Detained
- Unfit for slaughter (disposed as ABP)
- Humane killing whilst in the large on welfare grounds
Exceptions to OV ante-mortem inspection?
Emergency slaughter - PM performed by OV
Health certificate issued by OV or AV at farm - MHI satisfied it is satisfactory and welfare not compromised
When is emergency slaughter (unfit for transport) necessary?
a. Unable to move independently without pain or to walk unassisted
b. Present a severe open wound or prolapse
c. Pregnant females for whom 90% or more of the expected gestation period has already passed or females who have given birth in the previous week
d. Newborn and navel has not completely healed
e. Calves of <10do (unless transported <100km)
How long can animals be held in the lairage of a slaughterhouse? Food and water requirements? Other requirements?
No more than 48h (except chickens only few hours as no water or feed available)
If >12h: feed
Water at all times
Protection against adverse weather conditions
Protection against harm ex. by other animals and/or equipment and/or mal-practices
When can sick or injured animals be considered fit for transport?
a. Transport would not cause additional suffering
b. Transported for the purposes of Council Directive research programme
c. Transported under veterinary supervision for/following veterinary treatment or diagnosis (only where no unnecessary suffering or ill treatment is caused to the animals concerned)
d. Have been subjected to veterinary procedures in relation to farming practices such as dehorning or castration, provided that wounds have completely healed
In what cases can an animal be stopped from further processing at a slaughter house?
Dead on arrival (fallen stock)
Dead in lairage (fallen stock) - except emergency slaughter after OV inspection and approval
No FCI and traceability
No AM inspection by OV - except casualty slaughter, inspection by farm vet, PM inspection by OV
What is done if dead on arrivals (DOAs)?
Reported to APHA as suspected Welfare in Transport case
PM performed by APHA should the case result in a prosecution
Owner must be informed and allowed own vet to be present in PME
Lameness score by OV at AM inspection?
Score 1: visibly lame but can keep up with group
Score 2: unable to keep up with group
Score 3: requires assistance to rise, non weight bearing on one or more legs
Score 4: requires assistance to rise, non weight bearing on ne or more legs, reluctant to walk, halted movement, unable to climb steep ramps
Score 5: unable to rise or remain standing, extreme discomfort or vocalisation with assisted movement
Collect video evidence when OV reporting
Score 3-5: humanely killed without moving it elsewhere
Rules for non stun religious slaughter?
Unconsciousness before released from restraint for minimum of 20s (ovine) or 30s (bovine)
Dead before further dressed
Individually restrained -ruminants mechanically restrained
Minimise time of restraint
Only one live animal can be restrained at a time
Must be stationary for duration of the bleeding, until the animal is unconscious and for when the animal is killed without prior stunning
Restraining equipment must be checked and maintained in accordance with the manufacturer’s instructions
Contraventions: approval review
AM and PM examination findings of late pregnancy at slaughter?
AM:
- udder development (occurs earlier in heifers)
- enlargement of abdomen, particularly noted on right side
- swelling of vaginal area and vulval lips
- mucous discharge from vagina
- tail slightly raised an appear in discomfort if very close to birthing
PM:
- foetus close to term, with hair formation over entire body, eyelashes, open eyes and teeth in cattle, sheep and goats, usually ‘golden slippers’ present on the feet
Estimating the stage of gestation at slaughter PM?
Days of gestation - 2.5x(Crown to Rump length(CRL)+21)
CRL = top of head to buttocks length in cm
All animal species
How old must animals be for slaughter?
> 1 week
Rule for transportation of animals slaughtered on farm?
Must be refrigerated if transport takes >2h
Methods of enforcement of slaughter regulations?
Verbal
Escalates if non-compliance not corrected to written advice and formal notices
Referral for investigation
On site duties of FSA team (OVs) (slaughter)?
Auditing FBO responsibilities Welfare investigations Reporting of notifiable diseases to APHA Inspection - FCI, AM for fit/unfit for slaughter, PM for fit/unfit for human consumption Residue sampling Lab testing
When should an OV consider Certificate of Competences (CoC) suspension of the holder?
No longer a fit and proper person
No longer competent to carry out the operations which the CoC authorises
Has failed to comply with any provision of the EU Regulation or WATOK
Has been convicted of an offence under any animal welfare legislation
What are health marks?
Applied by the OV when official controls have not identified any deficiencies that would make the meat unfit for human consumption
Undergone AM and PM inspection and fit for human consumption
Examples of reasons to withhold health mark at PM?
No AM and/or PM inspection
Loss of traceability
Presence of SRM
Contamination or gross pathology
Residues or contaminants are suspected
Water supply found to be contaminated and a risk to public health exists
Animals suffering from a notifiable disease
Meat declared by OV as unfit for human consumption
No adequate inspection facilities rendering contamination or gross pathology inconspicuous
Temperature requirements for chilling and freezing of meat for human consumption?
Chilling: - red meat: 7C - white meat: 4C - offal: 3C Freezing: -20C (internal -12C?)
FSA statutory targeted sampling by member states for residue surveillance?
Cattle, sheep, goats, pigs, horses
Also wild game, farmed salmon/trout, eggs, honey, milk
Random selection but some exceptions
Fitness state not affected
Kidney, kidney fat, liver, muscle, blood and urine
EU requirement
Number determined by the VMD
Vet medicines, pesticides and heavy metals
What cattle specified risk materials are there for BSE?
Member states with controlled risk of BSE:
- All ages - tonsils, last 4m of SI, caecum, mesentery
- > 12mo - skull excluding the mandible and including the brain and eyes, and spinal cord
Member states with negligible risk of BSE:
- >12mo - skull excluding the mandible and including the brain and eyes, and spinal cord
What sheep specified risk materials for TSEs as of TSE regs 2006?
> 12mo or permanent incisor erupted:
- skull, including brain and eyes, tonsils, spinal cord (not horns)
Same for goats
What is done if discrepancies with traceability at slaughterhouse?
Detain carcass and passport
Keeper has 48h to correct
Report and/or enforce if necessary
If complete loss of traceability, animal killed and disposed of
Lapses without loss of traceability: OV reports to local authority, trading standards department
What must happen during investigation of a notifiable disease at a slaughterhouse, by an APHA veterinary officer (VO)?
Stop entry of animals
Stop slaughter
Isolate suspects and potentially contaminated carcasses
If suspicion can’t be ruled out:
- restriction notice closing establishment
- collect whatever samples are necessary for diagnostic purposes
If negative results: meat released
If positive: disposal of affected meat, cleaning and disinfection and in some cases premises rested for a period
Types of swine fever (notifiable disease)? What if suspected at AM?
Acute - petechial haemorrhages widespread, fevered carcass and LNs almost black
Chronic - necrotic skin lesions and ulcers in the intestine
If suspected, must not enter slaughter line - VO at APHA must be notified immediately
Anthrax - aetiology? Survival in environment? Transmission? Signs? PM?
Bacillus anthracis
Forms resistant spores that can survive for many years
Infection via ingestion and inhalation (and cutaneous e.g. skin wounds)
Sudden death following septicaemia <24h - take samples and diagnose, should not enter slaughter line!
PM: spleen grossly enlarged and dark, extensive petechiae, blood clots, dark blood
Bovine brucellosis - aetiology? Clinical signs?
Brucella abortus Abortion in late pregnancy High rate of infertility Inflammation of testes and epidydimis Swelling of scrotum Oedematous placenta and foetus Hygromas on the knees, stifles, hock and angle of the haunch and between the nuchal ligament and the primary thoracic spines
What to do if animals reacted positively or inconclusively for Brucellosis at slaughter? How is a decision then made?
Slaughtered separately
Hook should be used in handling the uterus and udder
Employees should wear gloves and avoid accidental cuts
Decision:
- Meat from animals with lesions indicating acute infection: unfit
- No lesions but reacting positively or inconclusively to test: udder, genital tract and blood unfit
Enzootic bovine leukosis? Cause? Age normally affected? What does it do? What will APHA do if suspected at slaughter?
Oncovirus in family retroviridae
> 3 years
? tumours other than papillomata or haemangiomata, or of swollen lymph nodes
Young normally sporadic leukosis
If <2 permanent incisors:
- no further action apart from recorded
If >3 permanent incisors:
- VO carry investigation so OV detains: samples of tumourous swollen lymph nodes/carcass or offals, carcass and offal doesn’t need to be detained pending results if no other changes
Aims of meat inspection?
To assess:
- pathology
- presence of SRM
- contamination SRM/faeces etc
- gross pathology
- evidence for residues or contaminants
How are humans infected by Trichinella spiralis? How bad is it?
Infection by consumption of undercooked meat
Life threatening to mild symptoms in 5-20 days
Cooking temperature required to inactivate Trichinella spiralis in pork? Freezing temp?
If instantaneously core of meat >62.2C
Freezing (instead of testing): minimum is -18C for 106h, max is -37C for 0.5h
Cold treatment is not an alternative for the testing of wild boar or solipeds (only for domestic pigs)
Temperature for what minimum time required for carcasses and offal with a localised Cysticercus bovis infestation (Taenia saginata)?
- 7C for at least 3 weeks
- 10C for at least 2 weeks
Signs of toxaemia in meat inspection? What must be done?
Uraemia with severe pyelonephritis
Ketosis with fatty change in the liver
Hold carcase for 24h and check by boiling/frying test
Unfit for human consumption if smell still present
Forms of sporadic bovine lymphosarcoma? Age affected? Cause? Fit for human consumption?
Most common malignancy of cattle
Cause unknown
Young cattle 6mo - 2yo
Multicentric: all LNs massively enlarged and replaced by white homogenous tumour tissue
Thymic lymphosarcoma: large swelling in cardiac and cervical parts of the thymus
Unfit for human consumption
Mild, acute/septicaemic, chronic erisipelthrix - fit for human consumption?
Mild type (diamonds on skin, poss bacteraemia) - depends on lesions Acute or septicaemic - total rejection Chronic (arthritis, endocarditis, enlarged LNs) - local or total rejection depending on severity and extension of the lesions
Examples of meat findings which make it unfit for human consumption?
Jaundice Septicaemia Pyaemia Emaciation Toxaemia Viraemia Malignant tumours White muscle disease Hydrocachexia
Is vertebral porphyria fit for human consumption?
Partial rejection
Callus formations following fractures - fit for human consumption?
Partial rejection
Depending on extent/localisation of callus could imply welfare issue at farm
Calcification - fit for human consumption?
Partial rejection
Gross pathology with Echinococcus granulosus on meat inspection?
Thickened, laminated outer membrane and filled with clear fluid
Scolices develop from the inner lining of the cyst and form ‘hydatid sand’
Cysticercus bovis cysts (Taenia saginata)- fit for human consumption?
One or multiple localised cyst (viable or non viable) - reject affected organ/parts, cold storage of remainder
Generalised non viable (caseous/calcified) - reject affected organs/parts, cold storage of remainder
Generalised viable - reject carcass and offal
When must the FCI for poultry be received by the slaughterhouse?
24h in advance
Exceptions to birds only being accepted alive at the slaughterhouse?
Delayed eviscerated poultry, geese and ducks raised for foie gras
Animals slaughtered at the place of production
Wild game
When must poultry dead on arrival (DOA) be reported to APHA?
Smaller poultry >1.5%
Larger poultry >2.5%
Salmonella testing of poultry for slaughter?
Holding:
- >2000 broilers or
- >500 turkeys
- >250 hens
- >350 laying chickens for class A eggs and not supplying final consumer/local retailers
Organic or slow growing (>81 days broilers, 100 days turkeys) is 6 weeks PM
Breeding (<250) test every 3 weeks (chickens, turkeys) or eggs 4 weeks
Laying chicks: adults 22-26wo and every 15 weeks, pullets 2 weeks before moving to laying unit (between 14-17wo)
Samples from flocks needed within a 3 week period prior to slaughter:
- boot swab sample
- dust sample
- faecal sample
Official sampling by APHA or DARD if:
- all your flocks after your previous set of flocks texted positive
- no evidence of testing or where National control scheme (NCP) rules haven’t been followed
What must be done to slaughter when positive on farm salmonella testing for chickens?
Retain affected batch(es) and slaughter at the of the production day
After slaughter, undertake full cleansing and disinfection of all equipment and machinery
Which Salmonella serogroups are high risk?
B and D
What is the minimum space allowance for poultry at slaughter for enriched cages?
750cm squared/bird
Minimum height of 45cm
Inc facilities for perching, nesting and scratching
Stocking densities for ante-mortem inspection of poultry?
<1.6kg: 180-200 cm2/kg
1.6-3kg: 160cm2/kg
3-5kg: 115cm2/kg
>5kg: 105cm2/kg
Minimum time for poultry to be dead before further dressed where not stunned under religious slaughter practices?
Turkey or goose: 2 minutes
Other birds: 90 seconds
How long must slaughter CCTV be kept for and where must it be?
90 days
Killing and where live animals are present - unloading, lairage, stunning
Should be available to FSA Authorised Officers
Signs of avian influenza at slaughter?
Pneumonia and airsacculitis
Haemorrhage
Oedema and discolouration
Common abnormal conditions of poultry seen at slaughter?
Septicaemia/toxaemia - very prevalent
Mechanical damage - normally result of poor functioning of the poultry plant machinery, FBO must be informed by OV if not already identified the problem
What must be done if stun to kill occurring to poultry?
OV must give written advice to FBO after each incident
A WEN should be served to slow down the line if it is due to line speed, shortage of slaughter men or lack of rotation
Referred for investigation if >3/3 month, enforcement record issues or series of incidents
Requirements for retailers of wild game?
Traceability - Reg (EC) 178/2002
Hygiene requirements Reg 852/2004 including T, HACCP, transport
Ante-mortem inspection requirements of farmed game, slaughtered on farm?
Inspected at AM by OV or approved veterinarian (AV) within 3 days of slaughter
Bodies accompanied by:
- veterinary health certificate
- FCI
- humane slaughter declaration from the FBO
- if >2h transport: refrigerated
Ante-mortem inspection requirements of wild game?
Hunters declaration/documentation
Pre-processing
FBA should examine carcass prior to entry into processing area: death other than hunting, extensive contamination, HACCP
Requirements of an Approved Game Handling Establishment (AGE)?
Approved by FSA OV Duties include: - verification of the hunter's status as a trained person (ex. copy of certificate) - HACCP in place - approved protocols for handling ABP
Traceability requirements for farmed deer?
Ear tags (TB order) and passports
- DEFRA herd number, or British Deer Farmers Association (BDFA) herd registration number
- animal’s own unique number
Breeder FCI with:
- identity
- veterinary products/treatments administered inc dates and withdrawal periods
Requirements of a trained person for documenting wild game at slaughter? What must they be able to recognise?
FSA approved training Registered as food business with LA Knowledge of abnormal characteristics Abnormal behaviour: - Non apprehensive towards humans - Aggression - Isolation from herd - Locomotive difficulties - Head tilt - Abnormal gait - Abnormal posture ex. bird with neck flexed and opening beak and wings - Slow at escape Environmental contamination: - pollution - heavy metals - phytosanitary treatments Other abnormalities: - diarrhoea exc waterfowl
Causes of abnormal behaviour/locomotion of game?
Parasites CWD Tumour Infection 0 Lyme disease, Louping ill, pigeon paramyxovirus Toxaemia
Trained person duties for examining wild game bodies?
Muscle bulk
- highly active animals but no nutritional support
- lean vs emaciated
Mucosae
Natural orificesTraumatic lesions - raging, systemic repercussions
Trained person duties for examining viscera of wild game?
Odour Colour Gas Perforation Oedema/transudate/exudate Haemorrhages Adherences, parasites If abnormal: must accompany the carcass
PM of farmed and wild game?
Farmed game - same as non game species, visual only for rabbits and ostriches
Wild game - either an MHI or OV is required for PM inspection, OV will visit at least once a month
Which farmed and wild game have residue surveillance? What is used?
Farmed - deer, partridge, pheasant, red grouse, quail, breeding boar
Wild game - deer, pheasant, partridge
Large game - kidney, kidney fat, liver and muscle
Small game - entire oven ready carcass of bird, passed as fit for human consumption, traceable
What must accompany wild boar carcasses for Trichinosis surveillance?
Head and diaphragm
What must happen if slaughterhouse case of TB?
OV must notify APHA
How much of small game must be PMd?
If batch uniform and same species and source: minimum of 5%
Batches <20: 100%
Placement and size of health mark on game carcasses?
6.5 x 4.5cm high
Letters 0.8cm high
Figures at least 1cm
Temperature requirement for storage of game?
4C small wild game
7C large wild game
Which bacteria/hazards are a risk for wild game birds?
E.coli O157 Salmonella Campylobacter jejuni Mycobacterium avium Chlaydophila psittaci (handling) Lead shot (consumption)
Which bacteria/hazards are a risk for wild ducks?
E.coli O157 Salmonella Campylobacter jejuni Mycobacterium avium Clostridium botulinum Lead shot (consumption)
Which bacteria/hazards are a risk for wild deer?
E.coli O157 Salmonella Campylobacter jejuni Mycobacterium avium Mycobacterium bovis
Which bacteria/hazards are a risk for wild lagomorphs?
Yersinia pseudotuberculosis Lead shot (consumption)
Porcine notifiable diseases?
African Swine Fever Anthrax Aujeszky’s disease Classical Swine Fever FMD Rabies Swine Vesicular Disease Teschen Vesicular stomatitis
Notifiable diseases in deer?
Foot and mouth disease Bovine tuberculosis Bluetongue Epizootic haemorrhagic virus disease CWD
Chronic wasting disease in deer - Transmission? Incubation? Clinical signs? PM? Zoonotic?
Transmission: body fluids (faeces, saliva, blood, urine) Incubation: 18-24 months Fatal in cervids Clinical signs: - poor body condition - separation from herd - difficulty swallowing - drooling - increased thirst and urination - nervousness and excitement - lowering of head, stumble - apathy, walk in repeated patterns, tremors, paralysis Post mortem: - serous atrophy of adipose tissue - muscular atrophy - aspiration pneumonia - liquid or frothy ruminal contents Zoonotic risk not confirmed
Signs of pigeon paramyxovirus? Zoonotic?
Lethargy Vomiting or regurgitation Green diarrhoea Trembling of wings and heads Twisting of the neck Head flicking Anorexia Dyspnea Discharge from eyes and beak Death ~ 3 days
Potential zoonosis - very rare, direct contact, mild conjunctivitis
Lyme disease - agent? pathology?
Borrelia burgdorferi
Non-erosive inflammatory arthropathy: arthritis and immune mediated renal failure
What are the 4 parameters for ranking meat borne hazards?
PISS: Prevalence on chilled carcases Incidence of human disease Severity of human disease Source attribution
Which meat-borne hazards are high risk in the context of meat inspection?
Campylobacter in poultry
Human pathogenic STEC in bovines and ovines/caprines
Salmonella enterica in bovines, porcine and poultry
Toxoplasma gondii in ovines/caprines
Trichinella in solids
What are HEIs?
Harmonised epidemiological indicators
= the prevalence, concentration or incidence of the hazard at a certain stage of the food chain that correlates to a human health risk caused by the hazard
What meat inspection conditions would result in the entire animal unfit for human consumption?
Septicaemia Pyaemia Jaundice Emaciation Toxaemia (some exceptions) Viraemia Anaemia Uraemia
What must be inspected as a minimum at PM for all bovines >6wo?
Head and throat
Sub-maxillary, retropharyngeal and parotid lymph nodes - incision
External masseters - 2 incisions must be made parallel to mandible
Internal masseters - incised along 1 plane
Tongue (palpate, and remove to also examine mouth and fauces)
Tonsils must be removed
Trachea and main branches of bronchi - open lengthways
Oesophagus
Lungs - palpated, incised in posterior third perpendicular to main axes (if for human consumption)
Pericardium and heart - incised lengthways to open ventricles and cut through IVS
Diaphragm
Liver - palpate, incise gastric surface and base of caudate lobe to examine bile ducts
Hepatic and pancreatic lymph - palpation
nodes
GIT
Mesentery
Gastric and mesenteric lymph nodes - palpation, incision if necessary
Spleen
Kidneys - incision if necessary
Renal lymph nodes - incision if necessary
Pleura and peritoneum
Genital organs (except penis if already discarded)
Udder and LNs - palpation and incision if necessary, each half of udder must be opened by a long, deep incision as far as the lactiferous sinuses (sinus lactiferes) and the lymph nodes must be incised, except when the udder is excluded from human consumption
What happens if a notifiable disease is suspected at AM e.g. anthrax?
Animal held in isolation
OV calls duty VO at APHA
VO may decide to visit
- if suspects ND then serves restrictions, OV follows instructions and informs FVC
- if doesn’t suspect ND and OV agrees, released for slaughter
- if OV doesn’t agree, OV calls contractor/FVC
If VO decides to not visit, OV calls contractor/FVC
If OV satisfied not a ND case, animal released for slaughter
If not, calls duty OV again
What material counts as SRM?
Cattle all ages: - tonsils - intestines from duodenum to rectum - mesentery Cattle >12mo: - skull excluding mandible and including brain and eyes - spinal cord
Sheep all ages:
- spleen
- ileum (60cm of terminal SI starting from ileo-caecal junction)
Sheep >12m (or permanent incisor erupted):
- skull including brain and eyes (not horns)
- tonsils
- spinal cord
What animal by product categories are there?
Category 1:
- all body parts of animals suspected/confirmed of being infected by a TSE, or killed due to TSE eradication measures
- all body parts of pets, zoo animals and circus animals
- all body parts of experimental animals
- all body parts of wild animals when suspected of being infected with diseases communicable to humans or animals
- specified risk material (SRM)
- entire bodies of animals which had not had SRM removed at the time of disposal
- products from animals which have had prohibited substances administered or contain residues of environmental contaminants
- all animal material collected when treating waste water from category 1 processing plants and other premises in which SRM is removed, including screenings, sludge from drains etc
- catering waste from means of transport operating internationally
- mixtures of category 1 material with either category 2 material or category 3 material or both
- category 1 ABP SRM must be destroyed by incineration or rendering and then incineration at an approved premises)
- category 1 non SRM can be rendered and land filled
Category 2 = pathologically altered and infectious material
- manure and digestive tract content
- all animal materials collected when treating waste water from slaughterhouses other than if they are Cat 1
- products of animal origin containing residues of veterinary drugs and contaminants (unless they are cat 1)
- products of animal origin, other than cat 1, that are imported from non member countries and fail to comply with veterinary requirements
- animals/parts, other than those referred to in article 4, that die other than by being slaughtered for human consumption, including animals killed to eradicate an epizootic disease
- mixtures of category 2 material with category 3 material
- animal by products other than category 1 or 3
- E.g. Taenia hydatigena, hydatid cysts from Echinococcus granulosus)
Category 3 = products not used for human consumption but fit for animal consumption
- parts which are fit for human consumption but are not intended for this for commercial reasons
- parts rejected as unfit for human consumption but are not affected by any signs of diseases communicable to humans or animals and derive from carcases that are fit for human consumption
- hides and skins, hooves and horns, pig bristles and feathers originating from animals that are slaughtered in a slaughterhouse, after undergoing ante-mortem inspection, and were fit, as a result of such inspection, for slaughter for human consumption
- blood obtained from animals other than ruminants that are slaughtered in a slaughterhouse, after undergoing ante-mortem inspection, and were fit, as a result of such inspection, for slaughter for human consumption
- animal by-products derived from the production of products intended for human consumption, including degreased bones and greaves;
- former foodstuffs of animal origin, or former foodstuffs containing products of animal origin, other than catering waste, which are no longer intended for human consumption for commercial reasons or due to problems of manufacturing or packaging defects or other defects which do not present any risk to humans or animals;
- raw milk originating from animals that do not show clinical signs of any disease communicable through that product to humans or animals;
- fish or other sea animals, except sea mammals, caught in the open sea for the purposes of fishmeal production;
- fresh by-products from fish from plants manufacturing fish products for human consumption;
- shells, hatchery by-products and cracked egg by-products originating from animals which did not show clinical signs of any disease communicable through that product to humans or animals;
- blood, hides and skins, hooves, feathers, wool, horns, hair and fur originating from animals that did not show clinical signs of any disease communicable through that product to humans or animals;
- catering waste other than as referred to in Article 4(1)(e).
If categories mixed, becomes highest risk
Septicaemia:
- clinical signs?
- PM findings
- fit for transport?
- fit for human consumption?
Clinical signs: dehydration, pyrexia, muscle tremors, tachycardia, tachypnoea, depression, congestion, petechia
PM findings:
- decreased onset of rigor mortis
- deficient exsanguination seen as diffuse congestion of subcutaneous blood vessels
- fatty degeneration of liver
- diffuse lymphadenitis
- splenomegaly
- jaundice if haemolysis
- disseminated petechial haemorrhage if DIC
Unfit for transport (welfare)
Unfit for human consumption (detect on AM)
ABP category 2 (if no SRM present)
Emaciation: PM findings? Repercussions? For for transport? Fit for human consumption?
PM findings:
- diffuse skeletal muscle atrophy with prominent bones
- poor onset rigor mortis
- oedema (hypoproteinaemia)
- serous atrophy of adipose tissue
Reduced drug/toxin clearance so even if withdrawals met residues may be present
Immunosuppression
CNS disturbances
Shorter shelf life
Further action taken if welfare compromised
Unfit for human consumption
ABP category 2
Arthritis: implications? Fit for human consumption?
Further action if welfare compromised
If lesions indicate ongoing septicaemia , whole carcass unfit
If localised and no evidence of ongoing septicaemia, rejection of affected tissues
What is the SICCT test for TB? Restults? Se? Sp?
Single intradermal comparative cervical tuberculin skin test
- Day 1 - injection of avian (upper, or left if small) and bovine tuberculin (lower)
- Day 2 - read test 72 (+/-4)h later
Pass/negative:
- negative bovine reaction with a positive or negative avian reaction
- or positive bovine reaction equal to or less than a positive avian reaction
- if entire herd negative, no action taken or retraction may be lifted
Inconclusive (retest):
- positive bovine reaction no more than 4mm greater than a positive avian reaction
- or positive bovine reaction with negative avian reaction where difference is 4mm or less
- owner must decide whether to euthanase and test, or retest animal on farm after 60d
Reactor/Fail (remove):
- positive bovine reaction >4mm greater than a negative or positive avian reaction
- isolate, value, slaughter, examine, PM, sample, milk discard
- lab tests, culture, molecular methods
Se 80%
Sp 99.98%
What documentation is needed for a cow from a TB restricted premise?
Emergency slaughter certificate
TB movement licenses
Electronic notification by APHA sent to OV by noon the day before kill
What is done differently for slaughter from a TB restricted premise if animals from non TB restricted premises are also slaughtered there?
The slaughter should be done separately to avoid contamination of adjacent carcases
- last in the day before full cleaning and disinfection
- at any other time as long as cleaned and disinfected before slaughter of non suspect animals
- in separate slaughter hall used for diseases animals or those suspected of being diseased
Farmer must have marked animal with an orange stripe along the back
What is inspected for a TB reactor and slaughterhouse suspected cases of TB at PM if required by APHA?
Visual inspection, palpation and incision (criss-cross) of LN
Routine anyway: - retropharyngeal - parotid - submandibular/submaxillary - bronchial and mediastinal - lungs - pleura - hepatic - liver - mesenteric - supramammary Udder
Additional for TB:
- prescapular
- superficial inguinal
TB lesions most commonly found in retropharyngeal, bronchial, mediastinal, lungs and udder LNs
Is a TB animal fit for human consumption?
Generalised TB or TB lesions with emaciation = entire carcass and blood and offal rejected
Localised TB in a number of organs/areas = all unfit
Lesion in lymph nodes of only one organ or part of carcass = only affected organ/part and the associated lymph nodes are unfit
Reactor but no lesions - no further action, samples collected for further examination
What is sent for TB sampling after PM?
APHA decide based on herd history and current status
Altered supra-mammary nodes always submitted
If no lesions found, all bronchial, mediastinal, paired retropharyngeal lymph nodes are collected and any others if enlarged, abnormal and/or haemorrhagic
Ear sampling of TB?
DNA marking tag of reactor animals is required at day 2 of TB testing
Collects a small sample of tissue at time of tagging
What must be done if TB slaughterhouse case?
OV places carcases and parts immediately in detained area before additional detailed inspection carried out
Notify APHA immediately
If required by APHA take samples etc
Make decisions in terms of fitness
What do TB lesions look like?
Often encapsulated
Granuloma with caseous and often partly mineralised centre
Can liquefy and become suppurative
How to know if a cysticercus bovis cyst is viable or non viable?
Non viable = caseous/calcified
Can determine by incubating in 1 70% saline solution and 30% bile at 37C for 30 mins - evagination of head if viable
ABP category for general pneumonia? Fitnesss for human consumption?
Rejection of affected tissues
All unfit if ongoing septicaemia e.g. multiple sites with abscesses
ABP 2
Are the following fit for human consumption? ABP category if not?
Mycoplasma like pneumonia in sheep Pasteurella like pneumonia in sheep Dictyocaulus filaria/viviparus Muellerius capillaris Lung melanosis
Mycoplasma like and Pasteurella like pneumonia in sheep: ABP 2, parts (lung) affected are unfit for human consumption
Dictyocaulus filaria/viviparus: ABP 2, parts (lung) affected are unfit for human consumption
Muellerius capillaris and lung melanosis: ABP 3, parts (lung) affected are unfit for human consumption
What is “Blood splash”?
Petechial/echymottic haemorrhages on sub pleural surface of the lung and epicardial surface of the heart
Predisposed by stress and dehydration at time of stunning
Sudden increase in BP at electrical stunning
When to suspect anthrax at slaughter? What to do?
Dark unclothed blood from openings
Suspect and animals in direct contact must be detained, isolated and reported to APHA duty VO immediately
If suspected at PM:
- carcase and associated parts detained away from human contact until results received
- all other carcases/offal should be detained
- stop entry of further animals
- lairage not to be cleaned or waste removed unless APHA authorised (if confirmed/inconculisve FBO to thoroughly clean and disinfect)
What to do with a DOA/DIL?
DOA reported to APHA/referred to LA as a suspected welfare in transport case
Ov not to perform necropsy since no conditions in lairage
DOA/DIL - carcass should not be opened, risk of anthrax, APHA notified immediately
Bovines >48mo FBO reports to a collector to be later tested for TSE
If TB reactor, OV reports APHA which will inform if samples required
Cysticercus tenuicollis: Aetiology? Pathogenesis? PM findings? Zoonotic? Fit for human consumption?
Taenia hydatigena
Sheep ingest eggs, larvae migrate through interstitial wall to liver, migrate through liver to abdominal cavity
Bladder like cysts
Can be mineralised
Not zozonotic
Affected tissues unfit (local rejection, affected organs disposed at category 2 ABP)
Hydatid cysts: Aetiology? PM findings? Zoonotic? Fit for human consumption?
Echinococcus granulosus
Thickened outer membrane, filled with clear fluid and ‘hydatid sand’
Human infection by ingestion of eggs in soil
Generalised (multiple locations) - whole carcass unfit
If not generalised, rejection of affected part
Disposal as category 2 ABP on public health grounds
Fluke: PM findings? Zoonotic? Fit for human consumption?
Haemorrage with immature parasites
Fibrosis of bile ducts
Nodular hyeprplasia
Human ingestion of metacercaria shed by water snails
Only liver unfit, unless lesions indicate hepatic function impaired greatly (in which case whole carcass unfit) ABP 3 (if no evidence of hepatic function impairment)
Are hepatic abscesses fit for human consumption? Appearance?
All unfit if septicaemia (multiple sites with abscesses)
Otherwise just rejection of affected tissue
ABP 2
Yellow pus with Staph/Strep
Green pus with Pseudomonas Aeruginosa
Onion ring like abscess with Corynebacterium pseudotuberculosis
Tumours: fit for human consumption?
Must consider possibility of enzootic bovine leukosis (notifiable)
Otherwise, entire carcass unfit if malignancy (infiltrative behaviour, metastases) or just affected tissues if benign
ABP 2
Ascaris suum: fit for human consumption?
Affected lobes of liver unfit (milk spot)
ABP 3
What is the FBO responsible for having in place?
SOP GGP If >1000 animals, AWO with GoC CoC for all stadd handling live animals Keeping records for 1 year
Responsible for HACCP and good practices (GAP, GMP etc) and risk assessments and FCI - OV audits the FBOs decision
What action is taken if an animal at a slaughterhouse is in pain and/or movement of animal would cause additional suffering?
If routine processing would not cause additional suffering:
- process routinely and OV to collect evidence
If routine processing would cause additional suffering:
- if FBO has not put procedures in place yet, instruct for animal to be killed in situ ASAP
- if FBo not aware and didn’t take measures, see where system failed and take enforcement measures
- if FBO aware take enforcement measures
Fitness for human consumption for animals with welfare problems?
If systemic condition, all carcass unfit
If localised, affected tissues trimmed and unfit
Can detain carcass/parts as evidence when enforcement is to be followed
ABP category if animal killed/found dead in lairage?
If ruminant with SRM = ABP 1
If other = ABP 2
What evidence is used for welfare problems at slaughter?
Clinical exam recordings Videos (e.g. lameness) Photos Detention of carcass CCTV Info regarding haulier/farmer etc
Who are farm/transport welfare cases reported to?
If urgent, reported to LA for transport or referred to APHA and reported to LA for farm
If non urgent, reported to APHA who will then contact LA if required
Recorded in FSA day book
Owner informed by FBO and allowed to also examine evidence
What is the FSA scoring for welfare states at slaughter?
Score 1 = compliance achieved
Score 2 = no immediate risk
Score 3 = potential risk to welfare but no harm caused (e.g. inadequate maintenance)
Score 4 = welfare critical (if unavoidable enforcement will not apply) - e.g. severely lame animal moved to stunning pen, DOA
What does religious non stun slaughter involve?
Ruminants:
- must be held upright in approved restraining pen, a head restraint required
- support to animal is required during and after slaughter
- not allowed in restraining pen unless ready
- fast and continuous incision through both carotid arteries and both jugular veins with sharp knife
- can’t be moved before 20 seconds (sheep) or 30 seconds
(cattle) and until animal is unconscious - animal can’t be further dressed before death
- back-up stunning system for emergencies
Birds:
- fast and continuous incision through both carotid
- can’t be further dressed/scalded before death and not before 2 mins in turkeys/geese and 90 seconds for others
What is done if a dirty or wet animal is found in the lairage?
Retained in lairage on clean bedding to clean/dry possibly overnight (no more than 48h)
Clipped to remove contaminated areas of wool/hair
Particular attention paid to areas where the first incision is made through the skin inc. ventral neck, sternum, linea alba and hocks
Killed in the lairage and carcase disposed - ABP disposal category dependent on species and material contained
Animal is slaughtered with a reduction in line speed to allow special care to be taken
Rejected if category 3 or 4 unless animal welfare grounds etc
Rejected if category 5
What is done if contaminated material found at PM?
E.g. Gi content, foreign material
Best practice is to trim affected area
Avoid washing as can spread contamination
What are anthacosis and carotenosis? Fit for human consumption?
Anthacosis = black pigment (carbon) in lung Carotenosis = yellow pigment of adipose tissue (most often in corn fed animals or older due to age related pigment accumulation) - fit for human consumption (ddx jaundice - unfit)
Deficient exsanguination: Appearance? Fitness for human consumption?
Dark red discolouration in the most ventral position of the carcass (head and neck when shackled by feet) and multifocal larger sized clots
Affected tissues unfit (more perishable)
If severe may be whole carcass unfit
How to determine if haemorrhage seen at PM was acute or chronic?
Minimal clotting if happened close to death
If 8h pre-slaughter, fibrin strands usually apparent
If within 24h pre-slaughter, red to red-blue and jelly like substance
If more than 24-48h prior to death tissue pigment will start being apparent and a soapy texture develops 72h post trauma
Fibrosis if older
What test is done if uraemia suspected due to the smell of a carcass?
Hold carcass for 24h and perform boiling test to assess if ureic smell prevails
Renal infarcts: fitness for human consumption?
If evidence of systemic involvement e.g. uraemia - entire carcass unfit
If localised lesion, only affected parts unfit
ABP 2
Hydronephrosis and urinary cysts: fitness for human consumption?
If localised only affected parts unfit
If systemic involvement ie uraemia all unfit
ABP 2
How is milk produced? What are the 3 types of milk secretion?
Synthesis (milk fat, protein, lactose) and diffusion (water, minerals, vitamins)
Milk secretion:
- merocrine = movement through epithelial cell membrane without injuring membrane (cows)
- holocrine = entire epithelial cell disintegrates to become part of the secretion (goats)
- apocrine = migration of secretory products to apex of epithelial cell, rupture of cell membrane to release (goats)
pH of milk, yogurt, better and cheese?
Yogurt: 4.4
Butter 6.1-6.4
Milk: 6.4-6.8
Cheese 4.8 (cottage) - 7.4 (camembert)
Water activity of whole milk?
> 0.9
What are the D and Z values?
D value = heat resistance of an organism, time at given temperature required to reduce population by 1log10 (90%)
Z value = temperature change required to alter D value by factor of 10
Types of pasteurisation? And UHT?
Low temp long time (LTLT): 63.5C for 30 mins
High temp short time (HTST): 72C for 15 seconds (25s recommended)
Flash: 88C for 1s
UHT: 135C for 1s
What is partially dehydrated and totally dehydrated milk?
Partially: up to 25% solids
Totally: no more than 5% water
Stages of cheese production?
Milk treatment and standardisation
Acidification: lactic acid producing bacteria or vinegar
Coagulation: proteins coagulate at low pH (rennet)
Suneresis: concentrating fat and protein in the curd
Maturation: secondary cultures plus drying
Main pathogens to be aware of in cheese?
Salmonella
Listeria
What is the phosphatase test?
Statutory test to assess efficiency of pasteurisation
Phosphatase enzyme should be inactivated during pasteurisation
Activity indicates pasteurisation not complete/contaminated
What is the peroxidase test for milk?
Lactoperoxidase is the enzyme most abundant in milk
Destroyed when >78C for 15s
Decrease indicates overheating = qualitative test
What is the resazurin test for milk?
Oxidation-reduction indicator in cell viability assays for bacteria and mammalian cells
Indicates contamination
pH and alcohol test for milk?
Femernation leads to release of alcohol and lactic acid
Indicates spoilage of normal milk
Delvo test for milk?
Presence of antibacterial substances
Based on inhibition go growth of Bacillus stearothermophilus var calidolactis (thermophilic bacteria v sensitive to many antibiotics and sulpha compound)
What microbiological criteria are there of milk?
Raw milk for consumption tested by farmer/processing/retailer:
- plate count (TVC) at 30C/ml <100,000 (2 samples per month, 2 month average)
0 SCC <400,000 (1 sample per month, 3 month average)
Raw milk for direct human cnsumtpino:
- plate count (TVC) at 30C/ml <20,000
- coliforms/ml <100
Raw milk by manufacturer:
- plate count (TVC) at 30C/ml <300,000
Processed milk by manufacturer:
- plate count (TVC) at 30C/ml <100,000
Definition of raw milk? Where banned? Rules?
Not been heated beyond 40C
Banned in Scotland and Ireland
May only be sold by registered holdings
Tb free cow/buffalo herd
Brucella free
Must have health warning (harmful in england, advise against children etc drinking in Wales)
Inspections twice a year for cow herds, only on risk basis for sheep/goats/buffalo
Cows: sampled and tested quarterly for TVC and coliforms
Main egg health risks?
Salmonella enteriditis - vertical transmission
Residues - pesticides, PCBs, anthelmintics, coccidiostat, antibiotics
Antibiotic defences of the egg shell?
Cuticle: made of glycoprotein, covers shell’s pores
She: calcium carbonate
Inner and outer membrane: protein fibres
Albumin: viscosity impedes microbe movement, pH 9.2, proteins:
- avidin: binds with biotin
- lysozyme: against gram positives
- ovotransferrin or conalbumin: antimicrobial
- ovoinhibitor: inhibits fungal proteases
Control principles for eggs?
Eggs that go for further processing: - from infected farms - damaged eggs - dirty eggs - old eggs Temperature at storage 20C for no more than 28d
Categories of eggs?
Class A: normal, clean, undamaged shell and cuticle, air space <6mm
Class B: normal shell, dirty, damaged cuticle, air space <9mm
Class C: Cracked or misshapen etc shell dirty, damaged cuticle, air space >9mm or damaged
What do egg stamps 0-3 mean?
0 = organic 1 = free range 2 = barn 3 = cage Plus individual producer code
Council Regulation (EC) 5/2001
What do double yolked eggs and blood spots mean?
Double yolk = young, highly productive laying hen had 2 ovulations
Blood spot = normal in or around yolk, blood vessel broke at time of yolk release, increased if high disturbance, less with free range due to rooting
What are meat spots and watery whites of eggs?
Meat spots = brown spot in albumin, more common in brown hens, small pieces of body tissue eg internal wall of oviduct
Watery whites = usually older birds, old eggs, IB
What causes green yolks and mobile/bubbly air spaces?
Green yolks = consumption of green herbage to excess
Mobile bubbly airspace = shell structure fault, airspace in albumen caused by ruptured inner membrane
What do black, red or green rots of eggs mean?
Bacterial or fungal contamination
Causes of coated egg shells?
Additional calcium (pink/lilac colour) when in shell gland for extended period of time, often in young flocks
Cause of a rough shelled egg?
2 eggs in shell gland at same time
Cause of pale shelled eggs?
Brown laying hens
Older laying hens in free range flocks
Disease
Causes of cracked eggs?
Most common reason for downgrading
Inadequate egg shell being laid or poor handling
What happens to the air space of an egg?
Egg is warmer than surroundings when laid
As it cools contents contract and air space forms between inner and outer shell membranes
As egg ages moisture and CO2 are lost through the pores
SO height of air space indicates quality and age of egg
Albumin quality?
Fresh good quality egg = jelly like, cloudy
Becomes transparent and watery as ages
Water migrates into yolk and shell so may become mottled and yolk enlarges
Albumin assessed by height in mm of outer thick albumin
What is the function of drying for egg processing?
Reduction of water activity
What are the 7 HACCP principles?
- Hazard analysis (biological, chemical or physical)
- Identify critical control points (CCPs) (steps used to eliminate a hazard or reduce it to an acceptable level)
- Establish critical limits for CCPs (max and min values, must be quantifiable e.g. temperature, water activity)
- Monitor the CCPs
- Establish corrective actions for when a CCP is not under control
- Verification and validation procedures to ensure procedures are working effectively (e.g. product testing)
- Documentation and records
= A preventative approach
Pre-requisties to HACCP?
Facility and equipment design Pest control Cleaning and sanitation Purchasing requirements Supplier approval Employee training Personal hygiene Foreign material control Water/ice/air control Product specifications Product storage control Equipment maintenance Transportation Product traceability/ retrieval/recall Record maintenance Allergen and chemical control
What to do with pig carcass if petechial haemorrhages, haemorrhagic lymph nodes and skin lesions that were missed on ante-mortem inspection? Why?
Total rejection of carcass and samples collected for further examination
Animal health/legal grounds
What to do with ovine carcass with Cysticercus ovis in many muscles? Why?
Local/partial rejection (if <4 locations?)
Affected organ disposed as Category 2 animal by-products
Aesthetic grounds
What to do with a ram carcass with generalised chronic purulent arthritis detected during AM and confirmed on PM
Total rejection of carcass and disposal as category 1 ABP
What to do with FBO ELISA results from pig carcassess confirming they are positive for Salmonellosis (carcasses currently in chiller)?
No further action regarding the carcasses
What to do with 7yo cow that farmer brings to abattoir to be slaughtered and wants to take home directly after slaughter and dressing, to use after maturing? Why?
Carcass detained until test results return from lab
Public health grounds
What to do if on PM there is calcified granulomatous lesions at retropharyngeal and mediastinal lymph nodes of one cow and TP suspected, so affected parts separated?
Partial rejection of carcass. Samples collected for further examination
Which zoonotic disease to be concerned about:
- flock of 60 suckler cows and 800 mules and half breds
- upland pasture
- three streams running down to provide reservoir for water source for people
- calving inside Feb-June
- lambing march-may outside
- approx 30% lambs born were treated for watery diarrhoea when 2-4 weeks old (assumed coccidiosis), but treatment disappointing with 5% mortality rate
- people now have watery diarrhoea, nausea and occasional vomiting
Cryptosporidiosis
What does ALOP stand for? What is it?
Appropriate level of protection
= The level of protection deemed appropriate by the member (country) establishing a sanitary or phytosanitary measure to protect human, animal and plant life or health within its territory
What does FSO stand for? What is it?
Food safety objective
= the maximum frequency and/or concentration of a hazard in a food at the time of consumption that provides or contributes to the ALOP
(point of food chain where the hazard level can no longer change)
What does PO stand for? What is it?
Performance objective
= the maximum frequency and/or concentration of a hazard at a specified step in the food chain, before the time of consumption that provides or contributes to an FSO or ALOP
What does PC stand for? What is it?
Performance criteria
= the effect in frequency and/or concentration of a hazard in a food that must be achieved by the application of one or more control measures to provide or contribute to a PO or an FSO
E.g. 6D reduction of Salmonella when cooking ground beef
= ‘acceptable level’ to be achieved at a critical control point (CCP) in HACCP context
What does PrC stand for? What is it?
Process criteria
= The physical process control parameter (e.g. time, temperature) at a specified step that can be applied to achieve a Performance Objective or Performance Criterion (CAC, 2005)
E.g. control parameters for milk pasteurisation are 71.7C for 15s to assure at least 6 log reduction of Listeria monocytogenes and destruction of Coxiella brunetti
= critical limits on Critical control points (CCP)s in a HACCP plans
What makes up risk analysis for the food chain?
Risk assessment/characterisation:
- hazard identification: is particular agent a public health hazard when present in food?
- hazard characterisation: what is the nature of the adverse effects associated with the agent in the food on the consumer?
- exposure assessment: what is the level of the agent in the food at the time of consumption?
- so overall risk characterisation: what is the overall probability of occurrence and severity of adverse health effects in population
Risk communication
Risk management
What does the government aim for with campylobacter of chickens?
Reduce the percentage of chickens that have a higher level of contamination (>1000 CFU per gram)
Because higher counts are associated with increased public health risk
Statutory requirement regulations for abattoirs?
Regulation (EC) No 852/2004
Regulation (EC) No 853/2004
Approval recommended by FSA veterinary official
What is HACCP?
= Hazard, Analysis, Critical, Control, Point
= a scientific preventative approach
Who regulates abattoirs?
England and Wales - Food Standards Agency
Scotland - Food Standards Scotland
Northern Ireland - Department of Agriculture, Environment and Rural Affairs
What does GMP stand for? What is it?
Good manufacturing Practices
Created in consultancy between government and stakeholders/industry
= Guidelines to ensure products are consistently produced to a standard that complies with statutory requirements
More descriptive than regulations
Covers all aspects of production including:
- Sourcing
- Equipment and its maintenance
- Training, health certificates and personal hygiene of staff
What does GHP stand for? What is it?
Good hygiene practices
= Guidance on good hygiene practice for the control of hazards in primary production and associated operations.
More descriptive than regulations
GHP cover all aspects of production:
- checks on food chain information
- the design and maintenance of premises and equipment
- pre-operational, operational and post-operational hygiene
- personal hygiene
- training in hygiene and in work procedures
- pest control
- water quality
- temperature control
- controls on food entering and leaving the establishment, and any accompanying documentation
What does an ante-mortem inspection by an OV involve, for white meat?
FCI received 24h in advance
Inspection of live birds - listening to the birds and observation, checking posture, wattle colour
Health certificate: on farm, MHI on site
Dead on arrivals (DOAs) reported to APHA if smaller poultry >1.5%, larger poultry >2.5%
What to do for slaughter of TB inconclusive reactors (IR) and direct contacts (DR)?
Slaughter:
- last in the day
- or any other time provided cleaning and disinfection
- separate slaughter hall
What to do if suspect warble fly at slaughterhouse?
Notifiable
Inform VO at APHA
If slaughter necessary prior to arrival of VO, the carcass and hide along with identifying ear tag should be detained for inspection by VO
A 7ml vacutainer sample of clotted blood should be collected at sample
Which parts of the body at PM are tested for TSEs?
Bovine - brainstem
Ovine/caprine - brainstem and cerebellum
Guidelines for age estimation using dentition of permanent incisors?
1 erupted: 541-806d 2 erupted: 536-825d 2 in wear: 584-1019d 3 erupted: 689-961d 4 erupted: 715-937d 4 in wear: 732-1275d 5 erupted: 902-1277d 6 erupted: 978-1304d 6 in wear: 980-1498d 7 erupted: 1038-1742d 8 erupted: 1098-1715d 8 in wear: 1103d+
What does CHORD stand for? What does it refer to?
Change Humans Organ Repercussions Disease status
Refers to meat fitness decisions
What are statutory meat inspection protocols?
Visual
Palpation
Incision
But varies with species and age e.g. pigs need visual inspection by default
How are the head and tongue inspected (as part of statutory meat inspection for bovine animals >6 weeks old)?
Visual inspection of head and throat:
- incision of the sub-maxillary, retropharyngeal and parotid lymph nodes
- examination of the external masseters, in which two incisions must be made parallel to the mandible
- examination of the internal masseters, which must be incised along one plane
- tongue must be freed to permit detailed visual inspection of mouth and fauces and must itself be visually inspected and palpated
- tonsils must be removed
How are the neck and thoracic organs inspected, except the heart (as part of statutory meat inspection for bovine animals >6 weeks old)?
Inspection of the trachea and oesophagus
Visual examination and palpation of the lungs
Incision and examination of the bronchial and mediastinal lymph nodes (Lnn. bifucationes, eparteriales and mediastinales)
The trachea and the main branches of the bronchi must be opened lengthways and the lungs must be incised in their posterior third, perpendicular to their main axes
These incisions are not necessary where the lungs are excluded from human consumption
How is the heart inspected (as part of statutory meat inspection for bovine animals >6 weeks old)?
Visual inspection of the pericardium and heart
Heart is incised lengthways so as to open the ventricles and cut through the interventricular septum
How are the gastrointestinal organs inspected (as part of statutory meat inspection for bovine animals >6 weeks old)?
Visual inspection of the diaphragm
Visual inspection and palpation of the liver and the hepatic and pancreatic lymph nodes, (Lnn portales)
Incision of the gastric surface of the liver and at the base of the caudate lobe to examine the bile ducts
Visual inspection of the gastro-intestinal tract, the mesentery, the gastric and mesenteric lymph nodes (Lnn. gastrici, mesenterici, craniales and caudales)
Palpation and, if necessary, incision of the gastric and mesenteric lymph nodes
How is the remaining carcass inspected (as part of statutory meat inspection for bovine animals >6 weeks old)?
Visual inspection
Residue sampling if applicable
FBO compliance with TSE testing and/or other ongoing protocols
Who does the FBO report to for welfare investigations of transport or farm?
APHA/trading standards
Decision made for carcass of pregnant female >90% of gestation, or female given birth in previous week, or under 7 days old?
Unfit for human consumption (should not have been transported in the first place!)
Decision for fitness of carcass with arthritis?
Non septic mild arthritis:
- clear or opaque synovial fluid
- very little cartilaginous wear
- slight hyperaemia of synovial membrane
- fit for consumption
Non septic more severe arthritis:
- increased, cloudy or blood coloured synovial fluid
- proliferation of synovial villi so synovial membrane appears covered in red pile
- synovial villi may be hypertrophied so much that they resemble polyps
- may be a chronic condition undergoing a flare up
- reject affected joint and check carcass and organs for signs of systemic disease (e.g. haemorrhages in kidneys and heart)
Septic or purulent arthritis:
- swollen joint
- marked increased of serosanguinous, turbid or purulent synovial fluid
- flocculi may be present in the synovial fluid
- joint villi are severely reactive
- synovial membrane is oedematous and thickened
- adjacent tendon sheaths may be infiltrated
- related lymph nodes are enlarged, congested, acutely inflamed and may also be endocarditis, kidney infarcts or pulmonary or uterine infectious foci
- condemn affected joint if mild/localised
- reject carcass if per-articular abscesses present in more than one joint
- reject carcass if severe case
- reject carcass if septicaemia
- check other organs and reject as necessary
What is porphyria? Cause? Signs?
The accumulation of plant or endogenous porphyrins in the blood resulting in tissue pigmentation and photosensitisation
This is a hereditary disease and is observed in cattle, swine and sheep
In porphyric cattle, exposure to light will initiate the development of photodynamic dermatitis
In swine, photodynamic dermatitis does not occur
What is a complication of liver fluke? Pathology?
Baccilary haemoglobinuria (Clostridium haemolyticum)
Spores reside in kupffer cells
Proliferate in low oxygen tension and form necrotic nidus
Release toxins including phospholipase C
Hepatocellular necrosis and intravascular haemolysis
What does osteomyelitis due to Trueperella pyogenes look like?
Pockets of green, semiliquid pus
OV tasks/responsibilites?
Auditing Inspection of: - FCI - ante-mortem - animal welfare - PM - SRM - lab testing
Pre-requisites for ante mortem in the abattoir?
Traceability met FCI Adequate facilities for examination: - lighting - facilities: crush for cattle, access to all animals, detention pen Operational requirements: - adequate training - AWO (animal welfare officer)
How is FCI for pigs done?
Online prior to delivery
What is done if dirty and/or wet livestock for slighter?
Corrective measures - clipping, bedding overnight
Or decrease speed of line so more attentive dressing
What happens if animals arrive with no FCI and are slaughtered pending its arrival, but it is not provided within 24h?
Declared unfit for human consumption and disposed of as ABP
How long should a vet set a withdrawal period for if not stated by product, for horses?
meat - 28d
milk - 7d
What meat borne human health hazards may be present at PM of pigs?
Not detected: - Salmonella enterica - Yersinia enterocolitica - Campylobacter spp. - Clostridium spp., - Listeria monocytogenes - VTEC - Antimicrobial resistance - HEV - Sarcocystis suihominis - Toxoplasma gondii Detected: - T sodium cysticercus (low se) - Trichinella (reliably)
Which meat borne biological hazards are ranked as high for bovines, ovines/caprines/porcines/solipeds and poultry?
Bovines: - human pathogenic STEC - Salmonella enterica Ovines/caprines: - human pathogenic STEC - Toxoplasma gondii Porcines: - Salmonella enterica Solipeds: - Trichinella Poultry: - Campylobacter - Salmonella enterica
How to do a HACCP?
- Assemble HACCP team
- Describe product
- Identify intended use and consumers
- Construct flow diagram which describes the process
- Confirm (verify) on-site flow diagram
- List all potential hazards, conduct a hazard analysis and consider control measures (HACCP principle 1)
7 - 12. Apply principles 2 - 7
Advantages and disadvantages of HACCP?
Advantages: - proactive and preventative - owned by the producers and staff - specific, systematic, scientific and documented Disadvantages: - expensive in the start - demanding of staff and time - difficult for small operators/large number of products
What are the industry and government responsible for, in relation to HACCP?
Industry:
- ensure proper application of HACCP principles and implementation of HACCP plan
- provide evidence of this to government authorities when requested
Government:
- facilitators: clarify goals and scope of HACCP, provide expertise when requested
- regulators: assess correct application and implementation of HACCP
- trainers: assist in or provide training programmes
Who audits the HACCP plan?
Vets (after FBO implements it)
EU HACCP law?
Article 5 of regulation (EC) No 852/2004
Which pathogen is the zero faecal tolerance (ZFT) critical control point of HACCP relevant for?
STEC - cause diarrhoea, haemorrhagic colitis and fatalities from haemolytic uraemia syndrome and ARF in humans (get from hamburger type food/ground meats)
Examples of physical, biological and chemical hazards?
Physical - metal fragments, wedding rings
Biological - bacteria, viruses, moulds, parasites, toxins
Chemical - lubricants, disinfectants, cleaning products, antibiotics, lead
Which step of beef production is the highest risk for STEC cross contamination?
De-hiding (hide is highly contaminated, meat is sterile)
What must the scalding tank temperature for pigs be? Why?
63 degrees as allows hair follicles to open up to be removed
Not hot enough to kill bacteria but any hotter would cook the product
Scalding tanks actually increase contamination risk
Singing process helps lower bacterial load
Examples of critical limit types?
Temperature Time pH Water activity Metal detection (number of metal pieces detected)
NOT rat bait for vermin control or PPE maintenance
What is microbiological criteria? Regulation?
A criterion defining the acceptability of a product, a batch of foodstuffs or a process, based on the absence, presence or number of microorganisms, and/or on the quantity of their toxins/metabolites, per unit(s) of mass, volume, area or batch
- food safety criteria are applied at retail level
Must include:
- the microorganisms of concern stated
- a qualitative or quantitative analytical method validated and chosen to give a sufficiently reliable estimate
- critical limits based on data appropriate to the food
- a sampling plan including the sampling procedure and decision criteria for a lot
Regulation (EC) No 2073/2005 on microbiological criteria for foodstuffs
What are the two types of microbiological criteria in the EU?
Food safety criteria:
- criterion defining the acceptability of a product placed on the market
- e.g. Salmonella absence in 25g of each of 5 samples of minced meat made from poultry meat during their shelf life on market
Process hygiene critieria:
- criterion indicating the acceptable functioning of the production process
- e.g. a presence of Salmonella in a maximum of 5 of 50 tested neck skin samples from 10 sampling sessions of poultry carcasses after chilling
What are microbiological standards?
Mandatory criteria
Used to determine the acceptability of a food with regard to a regulation or policy
Established by regulatory authorities
Foods not meeting the standard are subject to removal from the market
What are microbiological specifications?
Used by buyers of a food or ingredient to reduce the likelihood of purchasing a product that may be of unacceptable safety or quality
Buyers throughout the food systems establish microbiological specifications for materials they purchase
Specifications are advisory and the materials are sampled periodically
What are microbiological guidelines?
Established by either regulatory authorities, industrial trade associations or companies
Indicate the expected microbial content of a food when best practices are applied
Food companies use microbiological guidelines as a basis to design and assess their control systems (GHP, HACCP)
Advisory in nature and may not necessarily lead to rejection of a food
What are indicator organisms?
General microbiota:
- synonyms: total aerobic (viable) count (TAC/TVC) or aerobic plate/colony count (APC/ACC)
- indicates hygiene status of process, total bacterial load of product
Faecal coliforms, enterobactericeae, E.coli - indicates faecal contamination
What is the two class sampling plan for microbiological criteria?
Used almost exclusively for pathogens
Based on presence/absence
Consists of specifications:
- n = number of sample units to be examined
- m = maximum acceptable number of relevant bacteria/gr
- c = maximum acceptable number of sample units that may exceed the value of m (lot is rejected if this number is exceeded)
Interpretation:
- satisfactory if counts or values are below m
- unsatisfactory if counts or values are greater than m
What is the three class sampling plan for microbiological criteria?
Often applied for indicator organisms
Consist of specification:
- n = number of sample units to be examined
- m = maximum acceptable number of relevant bacteria/gr
- M used to separate acceptable from unsatisfactory
- c = number of sample units giving values between m and M
Interpretation:
- satisfactory if values are below m
- acceptable if a maximum of c/n values are between m and M, and the rest of the values observed are m or lower
- unsatisfactory if one or more of the values observed are >M or more than c/n values are between m and M
Severity of microbiological hazards?
Moderate: - S aureus toxin - V parahaemolyticus - B cereus - C perfringens Serious: - Salmonella (non Typhi) - Shigella - Listeria monocytogenes Severe: - EHEC (STEC, VTEC) - V cholerae O1 - C botulinum - EPEC - Cronobacter - L monocytogenes
How does stress affect meat quality?
Affects metabolism of glycogen in muscles:
- following slaughter, glycogen is converted to lactic acid
- amount of glycogen pre-slaughter affects pH after slaughter
- pH range for muscle following slaughter in range 7.0 - 5.0
Affected meat doesn’t eat or keep well
Acute stress:
- heightened awareness and increased metabolic activity before slaughter so fast excessive drop in pH to 5.2-5.4
- cooking losses
- pale, soft, exudative (PSE)
- predominantly pigs
Chronic stress:
- depletes glycogen so pH less acidic after slaughter (6-6.2 or up to 6.8)
- dark, firm, dry (DFD)
- shorter shelf life
- commonly beef
- also pigs and occasionally sheep
Difference between an invasive (penetrative) and non invasive (knocker) captive bolt?
Invasive: - impact with skull to produce stun - penetration of brain to prevent recovery Non invasive: - impact with skull to produce stun - skull fracture reduces effectiveness - mild tissue damage (haemorrhage) - limited to ruminants under 10kg live weight
Stunning position using invasive captive bolt, for cattle, sheep and pigs?
Cattle:
- crossing point between 2 imaginary lines drawn between eyes and centre of base of opposite horns
- bolt at right angle to skull so directed at brainstem
Polled sheep:
- highest point on head aiming straight down
Horned sheep:
- behind ridge between horns, aiming towards base of tongue
Pigs:
- 20mm above eye level on midline of forehead, aiming towards the tail
Amps required for head only electrical stun of pigs, sheep/goats, lambs/kids, calves and cattle?
Pigs: 1.3 Sheep/goats: 1.0 Lambs/kids: 0.6 Calves: 1.0 Cattle: 1.2
What is head to back stunning?
Produces cardiac arrest
Animal killed at point of stun
What problems are associated with catching poultry for slaughter? How to reduce problems?
Fractures and dislocations - legs, wings, necks Bruising Over stocking in crates Problems reduced by: - paper trail - education and training
What is included in PFCI (poultry food chain information, FCI)?
Owner and flock details including their vets
Mortality % at 14 days and to date
Vaccinations, medications and withdrawal periods
For this batch:
- history of disease
- other reasons for mortality e.g. floods
- tests and their results
For the holding:
- disease history particularly notifiable diseases and restrictions
- 2 previous consignments rejections and the main reasons for them
Signed by FBO and OV for approval
What should the time from hanging to slaughter of poultry be?
Approx 12s
What poultry are rejected for slaughter on arrival?
DOA
Injured birds
Small birds (likely to miss stunner, effects on current passing through other birds)
How long can birds hang legally before being stunned/killed?
Was:
- no more than 3 minutes for turkeys
- no more than 2 minutes for other birds
New legislation for shackle design:
- no more than 1 minute
- ducks, geese and turkeys no more than 2 minutes
Different types of electrical stunning of poultry?
Stun to kill:
- low frequency
- likelihood of regaining consciousness before the neck cutter is significantly reduced
High frequency stunning:
- improves meat quality (less broken bones, blood splashing)
- >100hz doesn’t generally induce heart attacks so stunned but alive
- bleeding must be accurate (severance of both carotid arteries)
How to identify an effective electrical stun in poultry (stunned but alive)?
Arched neck with head held vertically Eyes open No rhythmic breathing Rigidly extended legs (but can't use this identifier when shackled) Constant rapid body tremors Wings held tightly against body
What does the EU welfare in transport regulation (EC) No 1/2005, apply to?
Applies to transport of live vertebrate animals in connection with an economic activity:
- to slaughter
- to markets
- export
What protects non vertebrate animals and animals involved in non commercial movement?
domestic legislation (Article 4 of WATEO 2006 and parallel legislation in Scotland, Wales and Northern Ireland)
What is required to be in place when transporting livestock?
If >65km:
- must apply for and be granted a transporter authorisation
- driver must hold a valid certificate of competence
If >8h:
- vehicle must be inspected and approved
Animals must be accompanied with an animal transport certificate or a journey log
What transport authorisations are there?
Short journey (Type 1): - journeys >65km and up to 8h duration Long journey (Type 2): - >8h - covers both long and short journeys
How long can animals be transported for?
No more than 8h unless additional requirements carried out for long journeys (cows, sheep, pigs, goats)
If long journey provisions are met:
- unweaned calves, lambs, piglets and kids: max 9h, then at least 1h rest (given liquid, and if necessary fed), then max further 9h
- cattle sheep and goats: max 14h, then at least 1h rest (liquid +/- feed), then further max 14h
- pigs: max 24h, if >8h must have continuous access to water, except if <12h in total can just be offered at appropriate intervals
Journey time is from first animal loaded to last animal unloaded
If after this time, have not reached final destination, must be unloaded, fed and watered and be rested for 24h at EU approved control post
How long can poultry be transported for?
No maximum journey time
Must be provided food and water after 12h for adults, or after 24h for chicks (provided journey completed within 72h of hatching)
Journey time does not include time spent loading and unloading
No inspection and approval of poultry containers or vehicles is needed (even if >8h)
Space requirements for poultry during transport?
Day old chicks: 21-25cm2 per chick <1.6kg: 180-200cm2/kg 1.6-3kg: 160cm2/kg 3-5kg: 115cm2/kg >5kg: 105cm/kg
Religious slaughter: Methods recognised in legislation?
Jewish method: by a jew who holds a license (rabbinical commission)
Muslim method: by a muslim who holds a slaughter man license to perform religious slaughter
Qurbani/Udhia now also permitted: by a licensed muslim slaughter man in a licensed slaughterhouse which is under OV supervision
Can only be performed at approved red meat slaughterhouses
Religious slaughter: difference between kosher and halal?
Kosher: stunning not allowed
Halal: stunning accepted in many situations, approx 80% of animals are stunned
Pre requisites for an abattoir to be operational
Regulation (EC) No 852/2004
Hygiene provisions with regards to:
- Contamination arising from the air, soil, water, feed, fertilisers, veterinary medicinal products, plant protection products and biocides and the storage, handling and disposal of waste;
- Measures relating to animal health and welfare and plant health that have implications for human health, including programmes for the monitoring and control of zoonoses and zoonotic agents.
- Maintenance of equipment/facilities
- Hygiene of animals
- Potable water
- Training of staff
- Storage of hazardous substances
- Adequate response to test results
- Remedial action after problems identified during official controls
- Etc
E.g.:
- FCI
- lavatories for staff
- washing facilities in processing area
- BSE testing
- clean livestock policy
- actions following unsatisfactory results on HACCP
- non porous surfaces, including ceilings
- cleaning of equipment
- handling of food waste
- adequate protective clothing
- cold chain maintenance
- hygienic rapping materials
What do the following regulations relate to?
REGULATION (EC) No 854/2004 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 29 April 2004
Commission Regulation (EU) No142/2011 of 25February 2011 implementing Regulation (EC) No1069/2009 of the European Parliament
The Disease Control (England) (Wales) Order 2003
REGULATION (EC) No 854/2004 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 29 April 2004:
- laying down specific rules for the organisation of official controls on products of animal origin intended for human consumption
Commission Regulation (EU) No142/2011 of 25February 2011 implementing Regulation (EC) No1069/2009 of the European Parliament: - and of the Council laying down health rules as regards animal by-products and derived products not intended for human consumption and implementing Council Directive 97/78/EC as regards certain samples and items exempt from veterinary checks at the border under that Directive Text with EEA relevance
The Disease Control (England) (Wales) Order 2003:
- laying down rules as regards to movement restrictions
- ex. no animals to leave slaughterhouse except under the authority of a licence issued by APHA.
- licenses, cleansing and disinfection, enforcement etc
Pre-requisites for acceptance of an animal at abattoir?
Traceability met
FCI
Which is the most common zoonotic food borne disease? Which zoonotic food borne disease causes most deaths?
Campylobacter?
Salmonella
Most deaths = Listeria monocytogenes
Which legislation is important for drug usage and control of residues? Cascade levels?
The Animals, and Animal Products (Examination for Residues and Maximum Residue Limits) Regulations 1997 as amended (the ‘Residue Regulations’):
- offence to give any veterinary medicine to an animal unless has a marketing authorisation for their use in the UK
The Veterinary Medicines Regulations 2013:
- veterinarian must keep records of their use.
- vet can give other products under a ‘prescribing cascade’ when no medicines available
- level 1: use of a UK-authorised veterinary medicine indicated for the same species but for another condition or indicated for use in another species
- level 2: use of a UK-authorised human medicine or veterinary medicine authorised in the EU but not the UK, requires a Special Import Certificate
- level 3: specially prepared medicine made by a veterinary surgeon, pharmacist or suitably authorised manufacturer
Where are allowed substances/drugs for farm animals found?
Table 1 of Commission Regulation (EU) 37/2010
Maximum residue level is specified per product and prohibited
Where are essential substances/drugs for horses found?
Annex 1 COMMISSION REGULATION (EU) No 122/2013
Withdrawal period of 6 months
What is MRL? What is ADI?
The maximum concentration of residue accepted by the EU in a food product
Set for each edible tissue to endure the acceptable daily intake (ADI) is not exceeded
ADI calculated by adverse/observed effect level divided by an ‘uncertainty’ or ‘safety factor’ (amount eaten per day, metabolism, tissue distribution)
Withdrawal period calculated taking into account the rate of residue depletion, to below the MRL, in all edible tissues and products - conducted at European and national level (VMD)
Who collects on farm samples for residue testing?
APHA: live animals, animal feed, eggs and milk on farms
CEFAS: fish farms in England and Wales
Marine Scotland: fish farms in Scotland
National Bee Unit: honey samples in England and Wales
SGRPID: egg and honey samples from farms in Scotland
DARD: Northern Ireland
Order of slaughter process for cattle?
Lairage - AM Stunning Shackling Bleeding Dehiding (flaying) Evisceration Splitting of the carcass Final washing Chilling Deboning and cutting
Order of slaughter process for red meat?
AM Electrical/gas stunning Bleeding Scalding Dehairing Evisceration PM inspection Delivery
What EC hygiene regulations are there?
(EC) 852/2004 dealing with the hygiene of foodstuffs.
(EC) 853/2004 laying down specific hygiene rules for food
(EC) 854/2004 laying down specific rules for the organisation of official controls on products of animal origin intended for human consumption.
(EC) 2073/2005 on microbiological criteria for foodstuffs
(EC) 2075/2005 laying down specific rules on official controls for Trichinella in meat and
The domestic Food Safety and Hygiene (England) Regulations 2013
Food Hygiene (Wales) Regulations 2006.
What domestic regulations are there?
The Food Safety and Hygiene (England) Regulations 2013 and The Food Hygiene (Wales) Regulations 2006:
- provide enforcement powers in respect of the obligations that apply in Regulations (EC)852/2004, 853/2004,854/2004, 2073/2005 and 2075/2005.
The Official Feed and Food Controls (England / Wales) Regulations 2009- as amended
- Note: These provide enforcement powers in respect of the obligations that apply in Regulation (EC) 882/2004
The General Food Regulations 2004 (Wales)
The Food Safety and Hygiene (England) Regulations 2013 (England):
- Provide enforcement powers in respect of the obligations that apply in Regulation (EC) 178/2002.
What are local authority (Trading standard department) responsible for?
Producers supplying small quantities of meat from poultry and lagomorphs slaughtered on farm directly to the final consumer / local retailers.
Butchers’ shops (retailing meat to the final consumer or exempt under marginal, localised and restricted).
Any of the following not co-located with slaughterhouses, cutting plants or game handling establishments:
- meat preparations establishment
- minced meat establishment
- mechanically separated meat establishment
- processing plant (for meat products, rendered animal fats and greaves, treated stomachs, bladders and intestines, gelatine and collagen)
- cold stores where storage is the only activity
Premises manufacturing composite products containing meat and other edible co products.
Collection centres and tanneries that handle raw material for the production of collagen and gelatine
All the reasons to be unfit for human consumption?
(a) from animals that have not had AM inspection, except for hunted wild game;
(b) from animals the offal of which has not undergone PM inspection, unless otherwise provided or under this Regulation or Regulation (EC) No 853/2004;
(c) from animals which are dead before slaughter, stillborn, unborn or slaughtered under the age of 7;
(d) results from the trimming of sticking points;
(e) derives from animals affected by an OIE List A or, where appropriate, OIE List B disease, unless otherwise provided for in Section IV;
(f) from animals affected by a generalised disease, such as generalised septicaemia, pyaemia, toxaemia or viraemia;
(g) is not in conformity with microbiological criteria laid down under Community legislation to determine whether food may be placed on the market;
(h) parasitic infestation, unless otherwise provided for in Section IV;
(i) contains residues or contaminants in excess.
(j) from animals or carcases containing residues of forbidden substances or from animals that have been treated with forbidden substances;
(k) liver and kidneys of animals more than 2yo from regions revealed to have generalised presence of heavy metals in the environment;
(l) been treated illegally with decontaminating substances, ionising or UV-rays;
(n) contains foreign bodies (except, in the case of wild game, material used to hunt the animal);
(o) exceeds the maximum permitted radioactivity levels laid down under Community legislation;
(p) indicates patho-physiological changes, anomalies in consistency, insufficient bleeding (except for wild game) or
organoleptic anomalies, in particular a pronounced sexual odour;
(q) from emaciated animals;
(r) contains specified risk material (SRM), except as provided for under Community legislation;
(s) shows soiling, faecal or other contamination;
(t) consists of blood that may constitute a risk to public or animal health owing to the health status of any animal from which it derives or contamination arising during the slaughter process;
(u) in the opinion of the OV, after examination of all the relevant information, it may constitute a risk to public or animal health or is for any other reason not suitable for human consumption
Campylobacter testing?
Not carried out - poultry all assumed to be infected
What directive applies for intra-union trade in and imports from third countries of poultry and hatching eggs?
European Council Directive 2009/158/EC
Applies when:
- export >20 birds or hatching eggs to another EU member state or countries that require compliance with EU legislation
- sell birds or eggs to other PHS members
What testing requirements are needed by poultry farms for the poultry health scheme?
Salmonella testing of each flock at least once a year
Mycoplasma testing 4 weeks before point of lay and then every 12 weeks after during lay
Tested in a lab officially approved by DEFRA
What is an alternative to an OV AM for poultry?
Health certificate (3 days) signed on farm by an approved vet including all this information Trained meat hygiene inspector (MHI) checks welfare and health
Who collects red meat and poultry samples for residue surveillance from slaughterhouses?
FSA
Order of slaughter process for poultry?
Lairage
Stunning - gas (not ducks, unless argon) or electrical
Slaughter - automatic or manual (backup always needed)
Bleeding - severance of both carotids and jugulars
Scalding (average 55-57C for 2 minutes)
Plucking
Evisceration
Washing
Refrigeration to reach 4C
What if automatic stunning fails for poultry?
Always need a backup Manual dislocation: - up to 3kg live weight - person cannot do >70 birds/day If 3-5kg: - mechanical cervical dislocation must be used
Either can only be for back up, not routine
How long between stunning and bleeding of poultry?
2 mins for turkeys and geese
90s for other birds
What are animal by products?
animal carcases, parts of carcases or products of animal origin that are not intended for human consumption
Includes catering waste, used cooking oil, former foodstuffs, butcher and slaughterhouse waste, blood, feathers, wool, hides and skins, fallen stock, pet animals, zoo and circus animals, hunt trophies, manure, ova, embryos and semen
Which act was introduced which controls potential spread of Echinococcus to humans?
Dogs Act 1906
Made it an offence to leave any carcass on agricultural land where dogs can gain access
What does the Anthrax order 1938 (updated in 1991) do?
Gives the local authority the power to dispose of any carcase suspected of being affected by anthrax by incineration on the infected place
What animal by product legislations were put in place?
Specified Risk Materials Regulations 1997:
- controls in abattoirs for identification, removal and disposal of designated risk material from carcases
Animal By-Products Order 1999:
- introduced testing for enterobacteria risks
- Offence to allow access of ruminant animals to ruminant carcases
The Animal By-Products (Amendment) (England) Order 2001:
- banned feeding waste food to pigs
Animal By-Products Regulations 2003/2005/2009 made in accordance with Regulation (EC) 1774/2002:
- requires approval of all premises handling animal by products
Current: 2011:REGULATION (EC) No 1069/2009
How is category 1 ABP disposed of?
Incineration in licensed incinerators and the ash disposed in specially licensed landfills
Rendering with all products marked with glyceroltriheptanoate (GTH) Regulation (EC) 1432/2007
Special landfills for catering waste
Special derogations for remote areas
Has to be stained a nice blue… (patent blue V E131 an approved food additive)
How is category 2 ABP disposed of?
Incineration in licensed incinerators and the ash disposed in specially licensed landfills
Rendering with all products marked with glyceroltriheptanoate (GTH) Regulation (EC) 1432/2007 - composting and biogas after rendering
Oleochemical plants
Hunt kennels, maggot farms and zoos
Special derogations for remote areas
Has to be stained black (though it may look blue-gray…) with a solution of black PN or brilliant black BN (if >25kg or entire poultry carcass, surface opened by multiple deep incisions first)
Manure can go on land
What happens to category 3 ABP?
Pet food Composting and biogas Oleochemical plants Hunt kennels, maggot farms and zoos Special derogations for remote areas
What to do with carcass of poultry DOA or that was rejected at AM? What if was a cow?
Category 2 ABP
If was a cow, would be category 1
How big can drain traps or gratings be at salughterhouses to catch category 1 and 2 material?
Max 6mm
What can blood in pet food come from?
Pigs or poultry which have passed AM inspection
Ruminants which have passed AM and PM inspection
Which regulation bans burial of fallen stock on farms?
ABP regs 2003
Which fallen stock must be tested for TSE?
Cattle >24mo
Short version of what ABP categories there are?
Category 1:
- anything that has to do with TSEs
- whole ruminant carcasses
- zoo animals
- pets
- sick wild animals
- certain residue containing products
- international catering waste
Category 2:
- all meat unfit for human consumption except if has to with TSEs
- manure and digestive tract contents
- some residue containing products
- animals killed for disease control
Category 3:
- meat fit for human consumption but not intended for that
- all by products from animals that have undergone inspection and were found fit with some exceptions
What can be used for raw pet food?
Slaughterhouse material that was passed fit for humans to eat but is unwanted for commercial reasons
Fish by-products from factories and ships that prepare fish for human consumption
Game that was passed fit for humans to eat but rejected for commercial reasons, not due to disease
Material from animals that passed an ante-mortem test, that is unfit for humans to eat, eg liver with fluke
What can be used to make processed pet food?
Category 3 ABPs from carcasses passed fit for human consumption
Slaughterhouse by-products, like hides, skins, horns, feet, pig bristle, feather or blood
Heads of poultry
Milk production by-products
Materials from on-farm slaughter of rabbits or poultry
Hatchery waste, eggs, egg by-products and day-old chicks
Requirements for incineration of ABP?
On farm incinerators have to be approved by local authority or environment agency for ABP and others, or AH for carcasses
Low capacity incinerators (<50kg/hr): gas in the secondary chamber must achieve 850C for 2s (temp monitored by temp sensor)
High capacity incinerators (>50kg/hr): same as low, plus each line must have at least one axillary burner to assure the temperature is 850C during combustion
What is composting and biogas for ABP?
Composting = biological degradation under aerobic conditions
Biogas = biological degradation under anaerobic conditions to produce biogas
Heat treatment for at least 1h
Microbiological standards: absence of Salmonella in 25g
What is rendering?
Rendering = cooking parts of animals at high temperatures to make animal safe and reduce the water content to a storable level, then mechanical separation of tallow (fat) from solid residue which is put in storage for later incineration
To reduce scrapie to undetectable level, would need 133C at 3 bar pressure for min of 20mins
What are olechemical plants?
Process rendered fats for the production of fatty acids, rosins, terpenes etc
Who controls and inspects ABPs, with risk assessments of premises?
VO/APHA
FSA responsible for enforcement relating to ABP within approved slaughterhouses and cutting plants (local authorities responsible elsewhere, environment agency for very large incinerators)
When is optimum palatability achieved with chilling of meat?
After 2-3 weeks
Better tenderness and flavour
Involves acidification, rigor mortis and conditioning
What is acidification of meat? Effect on meat?
In the presence of oxygen:
- Glycogen breaks down to pyruvic acid and then to CO2 i H2O (with synthesis of ATP)
Without oxygen (post mortem):
- Glycogen breaks down to lactic acid
- = acidification (from pH 7.2 to pH 5.5)
- pH drops in beef muscle 36-48 hours, pig 4-8 hours
Effect:
- Protein denaturation, meat paler and more opaque - its ability to bind water decreases
What is the pH of normal meat PM?
Ultimate pH between 5.6-6.2
pH 1h PM: >6
What is rigor mortis? Effect of stress?
Controlled by the availability of ATP
ATP can no longer be generated by glycolysis and is eventually exhausted, so muscles lose relaxed state and pass into rigor
Stressed animals: less glycogen and ATP so more rapid rigor
Why is rigor mortis important for meat?
Fixes the length of the sarcomeres and therefore the muscle’s length and potential texture
Muscles entering rigor is a very contracted state -> tough meat
Muscles entering rigor in a relaxed or stretched state -> tender meat (hip suspension during chilling mechanically reduces shortening of the main muscles)
What is cold shortening? How slow to drop temperature?
Muscles should enter rigor mortis at 10-15C for optimum tenderness
Cold shortening = tough meat due to very fast chilling of carcassess immediately after slaughter (especially lamb, T<10C, pH>6)
Muscle temperature drop shouldn’t be below 10C in first 10h (beef) or 7h (pork)
What is electrical stimulation of meat?
Aim is to accelerate the pH decline after death in order to chill without risk of cold contraction/shortening
Electrical current passed through carcass to endure the meat is tender under rapid chilling
It accelerates the normal PM changes (depletion of glycogen and ATP) so muscle sets in rigor mortis sooner and can be chilled
What is conditioning of meat?
The resolution of rigor mortis
Natural process which improves eating quality of beef (flavour and tenderness)
Held under refrigerated and controlled storage conditions
Enzymatic proteolytic degradation -> tenderness
Rate of tenderisation differs with species and increases with temperature
Recommended ageing times before meat is consumed:
- poultry: 1 day
- pork: 4-10 days
- lamb: 7-14 days
- beef: 10-21 days
Chilling of meat: Why? When?
Critical for meat hygiene, safety, product shelf life, appearance and eating quality
Carcass chilling should start within 1h of exsanguination and occur so that a temperature of 4C or less is reached within 24h
And then cold chain until consumption!
What types of chilling of meat are there?
Slow air refrigeration:
- used rarely, in small abattoirs
- carcass ‘draining’ or ‘drying’ at ambient temperature for a few hours
- pre-refrigeration (around 10C, 75% relative air humidity - RH)
- refrigeration (4-7C, 85-90% RH)
- long time at ambient temperature for growth of microbes, relatively high weight loss (3%)
Rapid air refrigeration:
- most common
- carcasses exposed to air at 1 to -1C, 90% RH and 1-3m/sec circulation for 24-36h (cattle) or 18-24h (pigs, lambs)
- weight loss less (1.5-2%)
Ultra rapid air refrigeration:
- carcasses exposed to intensive circulation (2-4m/sec) of very cold (-4 to -6C) and humid (90-100%) air in special tunnels for 1-3h
- then refrigeration at -1 to 2C for 18-22h (cattle) or for 14-16h (pigs) with slow air circulation (0.1-0.3m/s)
- low weight loss (1%)
- problem is cold shortening
What is wet chilling?
Poultry offals and/or poultry if sold frozen
Problem is cross contamination and water absorption
What is the shelf life of meat with a temperature of -1 to 2C, RH 90% and air circulation 0.1-0.3m/s?
Beef: 3-4 weeks Veal: 3 weeks Lamb: 1-2 weeks Pig: 10-14 days Offals: 3 days
What chemical meat spoilage is there?
Putrefactive type spoilage: proteins -> polypeptides -> amino acids -> ammonia -> hydrogen sulphide and amines
Souring type spoilage: carbohydrates -> acids
Rancidity: oxidation of fats -> free fatty acids -> aldehydes/ketones
Colour change to grey, brown or green: changes of myoglobin into oxidised form
What causes sensory meat spoilage?
= unpleasant sensory characteristic consequence of the accumulation of a mixture of microbial metabolites
First stage: sweet, fruity odour (ethyl esters)
Advanced stage: putrid odour (accumulation of sulphur compounds, ammonia and amines):
- particularly if Pseudomonas is dominant
- and acetoin, diacetyl and 3-methylbutanol if Brochothrix thermosphacta is dominant
Ultimately signs of spoilage include meat greening (with or without fluorescence) and slime layer
Aerobic packaging of raw meat: What does it prevent? When is spoilage noticeable? Which bacteria are dominant at different temperatures? Shelf life?
Prevents secondary contamination, but doesn’t extend shelf life (shelf life 1-2 weeks)
Signs of spoilage become noticeable at microbial levels between 107/g (off-odour) and 108/g (slime), but not always
The composition of microbiota and their metabolic patterns more relevant for spoilage than the microbial numbers
At <5oC, dominant is Pseudomonas (lower pH; beef)
At >5oC, Brochotrix thermosphacta more dominant (higher pH; pork, lamb)
Poultry – similar but faster (higher initial contamination)
Aerobic packaging of minced meat: Problems? Dominant spoilage organisms?
Poorer microbial status due to:
- usually higher initial levels
- distribution of surface meat contamination throughout the product during mincing
- higher growth rate of bacteria due to damaged tissue membranes, finer structure and larger surface area in minced meat
Dominant spoilage organisms:
- Pseudomonas
- psychotrophic Enterobacteriaceae
Vacuum packaging of raw meat: What does this prevent? Problems? Shelf life? Requirements?
Vac-pac technology: exclusion of air from the package prevents growth of aerobes (e.g. Pseudomonas)
Problems:
- But proliferation of micro-aerophilic microbiota (lactic acid bacteria: Lactobacillus, Leuconostoc, Carnobacterium), in the case of low-pH
- Lactic acid produced: ‘dairy’ or ‘cheesy’ odour/flavour
Shelf life of 3 months for beef
Requirements:
- low bacterial level
- hygienic handling
- pH< 5.8 (otherwise green sulphomyoglobin)
- T< 2C (Clostridium botulinum)
Saturated CO2 atmosphere (100%) packaging for raw meat: What does it do? Dominant microbiota? Shelf life?
Gas impermeable packaging materials supress aerobes
CO2 eliminates oxidative rancidity of fats
Carbon dioxide dissolves in water on the meat surface - produces carbonic acid - lowers the surface pH of the meat
Dominant microbiota on saturated carbon dioxide packaged meat include Lactobacillus, Leuconostoc and Carnobacterium (similar to vacuum packaging)
Storage significantly longer (several months)
100% CO2 causes a brown colour of the meat - normal red colour recovers when packaging opened
Modified atmosphere packaging (MAP) for raw meat: What is it? Dominant bacteria?
Use of selected gases within an impermeable plastic pack
Oxygen: red colour - oxymyoglobin)
CO2: bacteriostatic, fungiostatic
Generally comprise of 60-75% CO2, 10-25% oxygen and 15-30% nitrogen
Type of spoilage depends on the gas composition:
- If high level of oxygen: pseudomonas (putrefactive)
- If higher level of CO2: lactic acid bacteria
Freezing of meat: temperature? Effect of rapid and slow freezing? When is water in meat frozen? When are bacteria and yeasts inhibited? Shelf life?
Freezing in industrial abattoirs normally carried out in ‘freezing tunnels’:
- air between 20-40C
- relative humidity of 95-100%
- circulation of 2-4 m/s.
Meat freezes (cryoscopy points) at between -1.5 and -1.8C (muscle tissue) and -2.2°C (fatty tissue)
Only 75% of water in meat frozen at - 5C, around 90% at - 30C and 100% at -60C
Bacteria inhibited at -7C, yeasts at 12C
Slow freezing: better survival of bacteria
Rapid freezing: water inside bacterial cell crystallises leading to cell death
Shelf life at -18C, RH 95-100C:
- beef: 12 months
- lamb: 8-9 months
- pork: 6-7 months
- poultry: 4-5 months
- oily fish: 2-3 months
What spoilage can happen to frozen meat?
Enzymes concentrated in liquid phase and active in frozen meat
- If frozen meat is stored non packaged, the surface ice can evaporate (sublimation) and the exposed meat can oxidise -> dry, discoloured patches (freezing burns)
- chemical spoilage: oxidation of fat (free fatty acids -> aldehydes/ketones) -> rancidity
Fatty tissues with a higher content of unsaturated and polyunsaturated fatty acids (soft fat) become rancid sooner
What is salting and curing?
2-6% salt and nitrate <200mg/kg
Salt reduces aw
Generates N-nitrosamines: carcinogenic
Gives a nice red/pink colour when cooked (nitrosylhaemochrome)
What is fermentation? How used for preservation of meat?
Phase of intensive growth and metabolism of lactic acid bacteria, accompanied with rapid fall of pH
Natural:
- aerobic gram negative flora of chilled meat (pseudomonas) replaced by gram-positive facultative anaerobes and micro-aerophiles (Micrococcus, Staphylococus, Lactobacillus)
- more acid-tolerant gram-negatives (E. coli O157, Salmonella) may persist
- gram-positive pathogens may grow if pH fall is slow or insufficient
Fermentation with starter cultures:
- same but faster
- competitiveness of starter organisms is a prerequisite
What products use fermentation?
Cheese, yogurt
Salami and fermented sausages
Buttermilk
What is smoking of meat?
= A result of aerobic or anaerobic pyrolysis of woods, their polysaccharides: cellulose, hemi-cellulose and lignin
Starts at around 170°C, and at temperatures up to 270°C is endothermic, and above that has an intensive exothermic nature
Cold (30C), warm (40-60C) or hot (70-80C) smoking
Can be hardwood smoke or liquid (injected):
- Drying
- Phenols and formaldehyde
- Temperature
What is drying of meat?
Removal of water
Methods:
- most often carried out by keeping product suspended in air
- lyophilisation: meat first frozen and then exposed to very low pressure of 5-6mbar in vacuum at 20-40C, 90% of water is removed, product remains same volume but 70% of the weight
What are the 3 groups of food after drying, based on aw?
- High-moisture products
- having an aw value of 0.9-1.0 (e.g. cooked sausage, cooked ham)
- those with aw >0.95 and pH >5.2 have to be refrigerated at <5°C
- those with aw 0.91-0.95 and pH >5.2 have to be refrigerated <10°C
- those with aw 0.9-0.95 and pH <5.0 can be stored without refrigeration - Intermediate-moisture products:
- having an aw value of 0.6-0.9 (e.g. dried ham, salami), that can be stored without refrigeration - Low-moisture products:
- having an aw value of <0.6 (e.g. lyophilized meat) that are self-stable
What heat treatments can be used for preservation of meat?
- Pasteurisation
- in water or steam <100C
- various sausages (70-80C), canned hames (62-68C) and hot smoked meats
- normally destroys all vegetative cells of psychrophilic and mesophilic microorganisms, but some vegetative cells of thermophilic bacteria, as well as all spores, can survive
- then stored with refrigeration - Boiling in water >100C
- product centre reaches 80-90C
- e.g. liver pate, black pudding, sausage
- kills all vegetative forms of microbes, but not spores
- products need refrigeration - Commercial ‘sterilisation’ at >100C
- usually in pressurized steam autoclaves, e.g. with canned meats sealed in a metal container treated at 105-130C (this kills all vegetative forms)
- spores either destroyed or injured to such an extent that they are rendered unable to germinate in the product
- Sterilized cans, such as so called botulinum-treated (e.g. 121C for 20 min in the centre), can be stored for years with no refrigeration
When is the microbial contamination of beef carcasses highest? Which bacteria mainly?
After dehiding (initially, carcass meat is sterile if animal is healthy) E. coli O157, Salmonella and Listeria monocytogenes
What are the main beef food borne pathogens in abattoirs?
E. coli O157, Salmonella and Listeria monocytogenes
What is immobilisation treatment of hides?
“Gluing” of bacteria to the hide
23% solution of food grade insect produced resin Shellac in ethanol
Spraying post slaughter, pre-skinning
Decontamination of hides: methods?
Steam pasteurisation: - 105C - Meat temperature >80C (>85C causes permanent damage) - if visible faecal spots <1in Knife trimming: - if >1" Hot water washing: - 80C Organic acids (lactic, acetic, citric, fumaric): Irradiation: Bacteriophage treatments Electricity (high voltage pulsed field) High pressure (400-450MNm-2)
What are the APHA responsible for?
Zoonosis surveillance (e.g. rabies, schmallenberg, Salmonella) Advise on control measures within veterinary remit (husbandry, hygiene, farming practices, disinfection)
What is the FSA responsible for?
Legislative criteria in food Food Safety Criteria Process Hygiene Criteria Primary production controls Food Chain Information FBO controls / FSA Audits
Consumer advice regarding burgers
Supplier testing
Functions outside slaughterhouses: - dairy hygiene inspections - shellfish controls (scotland) - wine standards inspections At slaughterhouses: - enforcement of animal welfare regulations - notifiable disease controls - TSE/BSE testing requirements - meat production adhering to legislation Veterinary surveillance at abattoirs: - AM, PM - drug residues - health marks
What are port health authorities responsible for?
Import of live animals and/or products of animal origin
Document check, identity check and physical check
Mycobacterium bovis (TB): Which lung lobes affected? Which lymph nodes most often affected?
Caudal lung lobes
Retropharyngeal and bronchomediastinal lymph nodes
Pathogenesis of bovine TB?
Inhalation
Bacteria enter macrophages in lungs
Reproduce in macrophages
Caseous necrosis -> liquifies
Clinical signs of TB in cattle?
Progressive weight loss Weakness Chronic low moist cough Loss of appetite Fluctuating pyrexia Mastitis Enlarged lymph nodes
Which legislation requires routine testing of cattle for TB
EU directive 64/432/EEC
Also national legislation since 1950s
What are the notifying requirements for TB?
Requirement to notify:
- suspected disease in bovines or deer
- suspected disease in a carcase of any bovine animal or other farmed or pet mammal
- presence ofM. boviswhich is identified by a laboratory examination of a sample taken from any mammal (except man) or from the carcase, products or surroundings of any such mammal
What action is taken if a TB reactor is found to have lesions typical of TB seen at PM or M bovis is isolated from PM samples?
TB is confirmed
Complete herd depopulation -> restock 60 days -> test 6 and 12 months
Or test and remove program with specified herd plan -> test until 2 clear tests
What action is taken if a TB reactor is found to be negative for TB at PM?
If low risk area - 1 clear test 60 days
If high risk area - 2 clear tests 60 days
What must happen to a herd if TB reactor?
- Movement restrictions
- immediately after suspicion through testing or PM inspection - Repeated testing (short interval testing):
- tuberculin skin tests every 60 days
- must have 1 or 2 clear consecutive tests before regain bovine TB free status (depending on PM findings)
- gamma interferon blood testing may also be used (compulsory for new lesions or culture positive TB breakdown in low incidence areas and edge areas) - Slaughter of any cattle that react to the test
- Cattle tracing
- Testing neighbourhood herds - risk basedd
Benefits/downsides of gamma interferon test for TB?
Can be used at shorter intervals Can detect infected animals earlier Could reduce the duration of herd restriction Less specific - more false positives More sensitive?
What TB moving testing is required?
Pre movement and post movement in Scotland
Pre movement in England and Wales (and post movement for low risk areas)
What notifiable diseases are there for cattle?
Anthrax BSE Brucella abortus Bluetongue CBPP Enzootic bovine leukosis FMD Lumpy skin disease Rabies Rift Valley fever Rinderpest TB (M bovis) Vesicular stomatitis Warble fly (Scotland only)
What is a notifiable disease?
A disease which is named in section 88 of the animal health act 1981 (cattle plague, pleuropneumonia, FMD, sheep pox, sheep scab, swine fever)
Or in an order made under the animal health act
Suspicion must be reported to APHA
Reasons to make a disease notifiable?
Public health significance (e.g. TB, anthrax, rabies)
Economic impact on agricultural industry (e.g. FMD, CSF, CBPP)
Impact on trade
Animal welfare impact (e.g. FMD)
Prevent introduction of exotic disease (e.g. FMD)
To collect information (e.g. Aujeszky’s)
To confirm absence (e.g. blue tongue, PED)
Which culicoides spread bluetongue? Is there a public health risk?
C imicola in Mediterranean
C obsoletes and/or C pulicaris in Europe
No public health risk
Bluetongue: Which animals affected? Is it notifiable?
All ruminants - sheep, cattle, deer, goats, camelids
Notifiable
What are the rules for porcine epidemic diarrhoea (PED) when notifying? How is it different to other notifiable diseases in pigs?
Pig keepers, their vets, or vet labs must report suspect and confirmed cases in pigs kept in England to APHA
APHA is permitted to share identifying details of suspected and confirmed cases to AHDB Pork (industry levy board) for disease control purposes
Unlike other notifiable diseases in pigs, no legislative requirement for official testing, culling, movement controls or other restrictions (Industry led rather than APHA)
Purposes of notifiable diseases?
To collect information To confirm absence To detect quickly To control as part of compulsory disease control programme by the state To facilitate international trade To prevent risks to the public
What notifiable diseases are there of sheep?
Anthrax Brucella melitensis Bluetongue Contagious agalactia Contagious epididymitis FMD Peste Des Petits Ruminants Rabies Rift Valley Fever Sheep and goat pox Scrapie
What notifiable diseases are there of pigs?
African Swine Fever Anthrax Aujeszky’s disease Classical Swine Fever FMD Rabies Swine Vesicular Disease Teschen Vesicular stomatitis Porcine Epidemic Diarrhoea
What notifiable diseases are there of poultry?
Newcastle disease
Avian Influenza
Pigeon Paramyxovirus
What notifiable diseases are there of horses?
African Horse Sickness Contagious Equine Metritis Dourine Epizootic Lymphangitis Equine Infectious Anaemia Equine Viral Arteritis Equine Viral Encephalomyelitis Glanders and Farcy Rabies Vesicular Stomatitis West Nile Fever
What notifiable diseases are there of deer?
TB Epizootic haemorrhagic virus disease Rabies Warble fly Anthrax FMD
What is the Animal Disease Notification System (ADNS)?
An EU system to allow rapid exchange of information between authorities responsible for animal health and disease
Allows monitoring of outbreaks and for measures to be taken to prevent spread
What is a reportable disease?
A disease which has statutory requirement to report laboratory confirmed isolation of organisms
Zoonoses Oder 1989:
- Salmonella and Brucella
- gives power to take samples, declare infected places, and to require cleansing and disinfection
Specified Animal Pathogens Order 2008:
- Trichinella
- Mycobacterium bovis
Foot and Mouth Disease (FMD): Aetiology? Which animals affected? Transmittion? Morbidity and mortality? Incubation period? Recovery time? Diagnosis?
Aetiology: - Picornaviridae, Aphthovirus - ssRNA - 7 distinct serotypes, not cross protective Animals affected: cloven hoofed (cattle, sheep, goats, camelids, pigs, deer) Tranmission: - aerosols or droplets - oral infection poor route in ruminants - pigs usually initially via oral - excreted in saliva, resp excretions, milk, semen, faeces, urine Morbidity: 100% Mortality: 2-20% Incubation period: 2-12 days Recovery: 2 weeks unless secondary infections Diagnosis: - virus isolation: tissue culture - antigen detection: ELISA, PCR - Ab detection: ELISA, SNT
Clinical signs of FMD in cows?
Drop in milk yield Rectal temperature 40.5C Drooling thick 'ropey' saliva Lip smacking Depressed, sick Uncomfortable on feet Vesicles on mouth - tongue, dental pad, hard palate, lips, muzzle, gums Vesicles on feet - coronary band, interdigital space Vesicles on teats and udder Vesicles rupture in 24h and heal after 1 week Abortion or still birth Death in young animals (myocarditis)
Clinical signs of FMD in sheep and goats?
Mild, if any, signs
Fever
Oral lesions
Lameness
Clinical signs of FMD in pigs?
Foot lesions - more severe than cattle, coronary band, heel, interdigital space Lameness Snout vesicles Oral vesicles less common Drooling is rare
Differentials to FMD?
Pigs: - Vesicular stomatitis - Swine vesicular disease - Vesicular exanthema of swine - Foot rot - Chemical and thermal burns Cattle: - Rinderpest, IBR, BVD, MCF, Bluetongue - Bovine mammilitis, Bovine papular stomatitis
FMD control measures?
- Restrict and control national movement of animals: (Licensing)
- Identify disease (reporting and surveillance, Vet inspections)
- Impose 3km protection zone and 10km surveillance zone
- Cull all animals on confirmed infected farms within 24 hours of first report.
- Cull all animals on dangerous contact farms
- Rapid and safe disposal of carcasses.
- Cleaning, disinfection and restocking
General food law for ‘due diligence’ to prevent contamination of the food chain?
Food Safety Act, 1990 and General Food Law (Regulation (EC) No 178/2002)
Who is the lead body that would respond in an incident of food/feed contamination?
FSA
What is the permitted level of lead in ruminant kidneys by EU law?
<0.5mg/kg Pb
What does red grain in gizzards and crops of laying hens and multiple carcase haemorrhages suggest?
Rodenticide poisoning
Bromodiolone rodenticide - who are at risk people if contaminated food?
Pregnant women
Those on warfarin
Human health risk from ragwort/pyrrolizidine alkaloids? When may food contamination occur?
Hepatotoxicity
Pulmonary toxicity
Increased long term cancer risk (carcinogens)
Food contamination can occur e.g. as a result of bee exposure
Likely low risk from milk and meat (lack of data)
What is needed for a batch of chickens to be accepted for further processing at a slaughterhouse?
Tested for Salmonella 3 weeks prior to slaughter
FCI received 24h in advance and be available for inspection
AM inspection done by OV evaluation of FCI and inspection of 20% of all live animals in batch
Must be alive prior to further processing (except for foie gras)
What happens to red meat carcass with:
- red neck
- generalised overscald >2mm deep
- mechanical damage affecting pectoral and leg muscles
- localised overscald >2mm deep
All total rejection
Except localised overscald >2mm deep -> local rejection of affected area
What causes ‘red neck’ chicken carcasses? What is the problem with it? How does it look different to DOA?
Due to severe hypostatic congestion of head and neck region due to inadequate exsanguination
If stun to kill: public health concern
If stunned with electrical bath and killed by exsanguination: public health and animal welfare concerns
DOA - lateral congestion as most ventral surface
What should the OV/FBO do if a 50 month old cow arrives dead to the abattoir?
Report the case to APHA and make a referral to Trading Standards as a suspected in welfare transport case
FBO should report the case to a collector so it can be tested later for BSE
OV should not perform the PM in the large because conditions are inadequate
What should the OV do if 40 month old cow found dead in the lairage with epistaxis?
Presence of unclotted blood oozing from nostrils and sudden death are suggestive of anthrax
APHA must be notified immediately
Carcase should be detained and so should all direct contacts (whilst alive) until further instructions
What should the OV do if finds a pig with vesicles and ulcers on the snout when doing AM? Similar lesions then found on the face and feet of 6 other animals?
Suggets infectious as multiple affected
Blisters besides ulcers has FMD as ddx
APHA should be notified immediately
Batch should be detained whilst alive until further instructions
When would there be total rejection of the carcass from a TB reactor?
Tubercles in mesenteric and mediastinal lymph nodes
Tubercles in udder and parotid lymph nodes
Why is PM inspection not part of HACCP?
Not delivered by FBO so FBO doesn’t have control over it
Which bacteria cause foodborne intoxication, invasive infection and toxico-infection?
Foodborne intoxication = organisms that produce specific toxins in the food that is ingested:
- Clostridium botulinum (adults)
- Staph aureus heat stable enterotoxin
- Bacillus cereus (emetic syndrome)
Invasive infections = bacteria ingested through food consumption, the organism invades and penetrates intestinal mucosa
- local enteric infection (non-typhoid Salmonella, Shigella, Campylobacter)
- systemic infection (typhoid Salmonella, Listeria monocytogenes)
Toxico-infection = bacteria ingested through food consumption, the organism produces toxins while in the GIT
- E coli O157:H7
- Vibrio cholerae
- Clostridium perfringens
- Bacillus cereus (diarrhoea syndrome)
Clostridium botulinum (infants)
Which gram negative food borne bacteria are there?
Enterobacteriaceae (facultatively anaerobic): - Salmonella - Yersinia enterocolitica - E coli O157 (and other VTEC) - Shigella Others: - Campylobacter (micro-aerophilic) - Vibrio (facultatively anaerobic)
Yersinia: food borne species? Characteristics? Infection routes? Incubation period? Disease in humans?
Yersinia enterocolitica (more prevalent) and Yersinia pseudotuberculosis Characteristics: - gram negative, non-sporogenic rods - facultatively anaerobic - non-motile at 35-37С - usually motile at 22-25С - temperature range 1-44C (28-29C optimal) - salt: can grow 5-7% NaCl - pH: 4.0-4.7
Incubation: 1-11 days (1-1.5 day)
Infection routes:
- pigs most important source: Y enterocolitica very common in throat, tonsils and faeces
- raw, minced pork
- also found in water, soil and dogs
Disease in humans:
- acute disease: fever, gastroenteritis, sometimes bloody diarrhoea, lymphadenitis (mesenteric), pseudo-appendicitis, septicaemia, liver (and other) abscesses
- secondary complications (1-3 weeks later): arthritis, erythema nodosum, myositis
Presence of Yersinia on food products? Which products? Other places?
1) Pigs and pork:
- asymptomatic carriers of Y. enterocolitica biotype 4 serotype О:3
- evisceration (handling heads-tonsils and tongue)
- psychrotroph
- raw pork products (meat, tongue)
2) Cattle and beef products
- asymptomatic carriers of serotype О:9
- possible cross-contamination from pork to beef during handling in butchers and retail
3) Milk and milk products
- inadequately pasteurised milk ideal environment for growth of psychrotrophic Y. enterocolitica
4) Vegetables
5) Others
- dog and cats
- wild rodents (biotype 1B serotype О:8 i О:21)
- water, ponds, lakes
How are pigs categorised for Yersinia risk at slaughter?
Pigs originated from controlled herds?
Seropositive (but unstable immune response)
How is contamination of pig meat by Yersinia avoided during slaughter?
Head removal before carcass splitting and removal of the tongue - hygienic transfer to separate line for further handling and inspection
Avoid palpation and incision during inspection
Tying the rectum
How is contamination of pig meat by Yersinia avoided after slaughter and dressing?
Maintaining cold chain (potential problems due to pychrotrophic nature)
Pasteurise milk and dairy products
Raw pork kept separate from other foods
Proper cooking - 72C for 2-3 mins
Vibrio: which species? Characteristics? Source?
Vibrio cholerae, parahaemolyticus and vulnificus
Characteristics:
- facultatively anaerobic halophilic (0.5-10% NaCl), alkaliphilic (pH 7.8-8.6), straight or curved, motile rods
- seawater or 2 to 3% (range 0.5 to 10%) NaCl is required for survival and growth
- growth in water: minimum 10-19C
Primary source is faecally contaminated water - marine water, estuaries
Cholera (Vibrio cholerae)? Incubation? Cause? Symptoms? Source?
Incubation 6h - 5 days
Toxico-infection
Disease caused by action of an enterotoxin produced by mainly the O1 & O139 serogroups
High infectious dose, 10^6 cells
Sources:
- poor sanitation, using contaminated water for food preparation or to drink
- shellfish - filtrate sea water and concentrate V cholerae
- seafood, including raw, lightly cooked or recontaminated shellfish or fish
Symptoms:
- profuse watery diarrhoea with ‘rice water’ stools (up to 10 litres per day)
- severe abdominal pain
- vomiting
- fluid loss can lead to severe dehydration, acidosis, shock and circulatory collapse
- death in few hours if not rehydrated
Control measures for cholera?
- Consume only potable water
- Dispose of sewage correctly
- Use only potable water in seafood harvesting and preparation
- Do not harvest seafood from waters containing Vibrio cholerae
- Avoid raw seafoods
- Chill seafood to <4°C at harvest and after
- Exclude infected individuals from handling food
Vibrio parahaemolyticus: pathogenesis? Sources? Incubation? Symptoms?
Similar characteristics and sources to V. cholerae (fish and shellfish)
Invades gut epithelial cells producing a haemolytic cytotoxin
leading to diarrhoea
Incubation 12-24h
Milder symptoms than cholera: - abdominal pain - diarrhoea - cramps - nausea - sometimes vomiting - low fever - chills - headache The disease is usually self-limiting
= The most common foodborne disease in Japan (raw sea foods)
Control measures similar to other Vibrio spp.
Vibrio vulnificus: Characteristics? Sources? Symptoms?
Similar characteristics to V. cholerae
Similar sources
Incubation 16-38h
Severe symptoms:
- septicaemic invasive infection
- fever
- nausea
- necrotic skin lesions
- death
Low infection dose, up to 100 cells
Control measures similar to other Vibrio spp.
People with liver disease or other chronic disease should not eat raw shellfish, particularly oysters
Listeria monocytogenes food borne pathogen: sources? Type of infection? Incubation? Difference between invasive and non invasive? Who is at risk?
Invasive infection
Sources:
- animal intestines (asymptomatic carriers) and humans
- ubiquitous in soil, water, plants, silage etc
- working surfaces in the food industry (can form persistent biofilms)
- ready to eat (RTE) foods: raw milk, soft cheeses, sliced deli products, vegetables, salads, unpasteurised juice, cooked meats, smoked fish
Characteristics:
- motile rod at 20-25C, non-motile at 37C
- facultative anaerobe, but prefers a microaerophilic atmosphere if O2 is present
- very resistant to drying
- growth at 4C (can grow at 0°C, even -1.5C) to 45C
- tolerates 10% NaCl
- tolerate low aw
- pH: 4.1-9.6
Invasive listeriosis:
- incubation 1-21 days
- invades GI mucosa -> macrophages -> bloodstream to CNS (meningitis) or foetus
- problem in immunocompromised people (pregnant, AIDS, cancer, young, elderly):
- septicaemia
- meningitis
- encephalitis
- abortion
Non-invasive listeriosis:
- mostly enteric diarrhoea, mild fever, headache, myalgia
- 1-3 day incubation
- healthy individuals at risk
Control measures for Listeriosis in food?
- Use GHP and HACCP in food production.
- Immunocompromised individuals and other target populations should avoid high-risk foods.
- Pasteurize milk and dairy products; don’t consume unpasteurized products.
- Prevent cross-contamination and recontamination of heat-treated foods.
- Completely separate raw and cooked products during meat product manufacture.
- Re-heat ready-to-eat foods adequately.
Minimum toxic doses for Staph aureus, Clostridium botulinum and Bacillus cereus?
S aureus: 10^6
C botulinum: 10^4 - 10^5
B cereus: 10^7 - 10^8
Staph aureus: food borne intoxication? Main sources? Characteristics? Incubation period? Symptoms?
= Staphyloenterotoxicosis
Characteristics:
- non-motile, facultative anaerobe
- extremely resistant to desiccation
- 8 toxins (A, B, C1, C2, C3, D, E, F) most common type A, then D
- growth at 7-46°C (enterotoxin not produced <8°C)
- pH: 4-9.8
- tolerate low aw
- tolerate 10% NaCl (and produce enterotoxin A)
- enterotoxin highly heat resistant (not inactivated by boiling at 100C)
Main sources:
- skin, hands, anterior nares (30-50% of people harbour it), skin lesions
- milk
- environment (dust vegetations)
Incubation 1-6h Main symptoms at 6-24h: - nausea - vomiting - diarrhoea - abdominal pain - no fever! - collapse and dehydration in severe cases
Control measures for Staph aureus in food?
- Use good personal hygiene practices when handling foods.
- People with skin infections should not handle foods.
- Use GHP when handling foods.
- Chill cooked food rapidly in small quantities.
- Store cooked or heat-treated foods at <4°C or >60°C.
- Avoid extensive handling of foods.
- Avoid delays between cooking and eating.
Clostridium botulinum in food: sources? pathogenesis? Types of disease? Symptoms? Incubation? Toxic dose? Characteristics?
Source:
- typically foodborne form caused by poorly canned, bottled foods or in honey
- major scares in 1970s from tinned salmon and corned beef
- soil, water, vegetables
- animal and human faeces (asymptomatic)
Pathogenesis:
- germinating spores in anaerobic environment lead to formation of vegetative cells that release a potent toxin
- toxin acts to block nerve synapsis causing paralysis and death
2 types of food borne disease:
- Botulism (intoxication)
- Infant botulism (toxico-infection)
12-36h onset Duration days to several months Symptoms: - nausea - vomiting - visual disturbances - vertigo
Proteolytic:
- toxins A, B, F
- Toxic dose: 0.005-0.2mcg
- minimum pH 4.6
- maximum NaCl 10%
- minimum Aw 0.93
- temperature range for growth 12.5-48C
- decimation reduction time of spores at 100C: 25 mins
- D value at 121C = 0.2 min
Non proteolytic:
- toxins B, E, F
- toxic dose 0.1-0.5mcg
- minimum pH 5
- maximum NaCl 3%
- minimum Aw 0.97
- temperature range for growth 3.5-48C
- decimation reduction time of spores at 100C: <0.1 min
- D value at 80C = 1 min
The ‘Botulinum cook’ is a 12D reduction of C. botulinum spores, i.e. 2.5 min at 121C
F0 of 3 minutes is the heat process required for a low acid canned food and will kill at least 10^12 spores
Toxin is sensitive to heat:
- treatment at 80C rapidly denatures toxin
- approx. 1000 x reduction of types A and B in 1 minute
- all toxins inactivated by heating at 80C for 30 minutes
Infant botulism: Why happens? What happens? Most common sauce? Symptoms?
Children under 1 year old do not have established gut microflora, so pathogen may colonize more easily
Organism is ingested and proliferates in GIT, producing toxin
Honey most common source
Neuromuscular symptoms similar to botulism, resulting in constipation, weak cry and respiratory distress
Usually self limited
Control measures of Clostridium botulinum in food?
- Avoid home canning of vegetables, fish and meats.
- Discard cans with faulty seals.
- Heat any suspect food to 80°C for 15 minutes to destroy toxin.
- Store home-canned foods at <3°C.
- Do not feed honey to babies or infants.
- Do not feed infants non-heat treated foods
Bacillus cereus: characteristics? Which foods and sources? Syndromes?
Characteristics:
- gram positive, spore forming, motile rod
- produces two toxins which are heat stable
- highly resistant spores and toxins
- D value of 0.02-0.06 minutes at 121C = 0.3-27 minutes at 100C
Sources:
- mainly pulses and rice
- also other raw food: cereals, dried vegetables, potatoes, milk, cream, spices
- also cooked: roast/fried meat products, soups, cooked/fried rice meals
- soil, dust, water, vegetation
Most often associated with cooked rice products kept at room temperature
2 syndromes:
- Emetic syndrome: intoxication:
- Infectious dose high (>10^5) so pathogen growth in food required
- vegetative cells killed by cooking, spores are not
- if cooked rice/pulses are not chilled, spores can germinate, bacteria grows and toxins produced -> ingestion of pre-formed toxin (intoxication)
- toxins are not destroyed by re-heating
- emetic toxin induces rapid and profuse vomiting (around 15 minutes after consumption, but up to 14h later)
- symptoms last 6-36h - Diarrhoeal syndrome: toxicoinfection
- spores or vegetative cells are ingested, and toxin is produced in the GIT (toxicoinfection)
- infectious dose high (10^5 - 10^8), so pathogen growth in food required
- enteric toxin induces profuse, painful but short-lived watery diarrhoea and abdominal pain(4-16 hours after consumption)
- symptoms last 12-24h
Control measures for Bacillus cereus in food?
Prepare food in small batches
Chill cooked food rapidly in small quantities
Store cooked food at <5°C or >60°C
Re-heat cooked foods thoroughly to kill vegetative cells
Clostridium perfringens: Characteristics? Sources? Symptoms? Incubation?
Characteristics:
- infection dose >10^6 (growth in the food)
Sources:
- Main type A toxin producing strains survive in animal GI tract (asymptomatic carriers) and soils, water, dust
- spores contaminate meat and may survive cooking (thermo resistant)
- contaminated foods, cooked in bulk and inadequately cooled
- cooking activates C. perfringens spores which germinate in the anaerobic conditions
- foods containing gravy, with long slow cooking, in bulk and in advance
- POORLY STORED COOKED MEAT (e.g. Xmas Turkey) including meat re-heated in mass catering allows germination and massive numbers of vegetative cells (>106)
Ingestion leads to sporulation of vegetative cells to produce enterotoxin production in small intestine leading to diarrhoea (toxicoinfection)
Incubation 8-24 h
Symptoms:
- Severe abdominal pain with profuse diarrhoea
The illness last for up to 2 days, recovery is usually complete (could be fatal in IC people)
Control measures for Clostridium perfringens in food?
Cook food thoroughly to kill vegetative cells
Chill cooked food, especially meat dishes, rapidly in small quantities
Store cooked food at <5°C or >60°C to prevent growth
Limit the storage interval for cooked food to reduce growth of survivors
Reheat food to at least 75°C to kill vegetative cells and to inactivate toxin if pre-formed in food
What gram positive foodborne pathogens are there?
Listeria monocytogenes Staphylococcus aureus Clostridium perfringens Clostridium botulinum Bacillus cereus
Difference between foodborne infection vs food poisoning?
Foodborne infection = infection with an agent (usually bacterial or viral) that results in (often diarrhoeal) disease
- frequently zoonotic
- e.g. Salmonella, E. coli, Norovirus
Food poisoning = the exposure to toxins (microbial or other) that results in disease
- frequently caused by contamination, poor storage or poor handling
- e.g. Staphylococcus toxin, Bacillus enterotoxin, afalotoxins from fungi
Salmonella enterica: Main sources in food? Symptoms in humans?
Main sources:
- meat
- eggs
- raw milk
- faecally contaminated fruit/veg
Symptoms:
- gastroenteritis - diarrhoea and vomiting
- fever
- sometimes invasive septicaemia
E. coli O157:H7: Main sources in food? Symptoms in humans?
Main sources:
- beef
- raw milk
- faecally contaminated fruit/veg
Symptoms:
- haemorrhagic diarrhoea
- renal failure
Campylobacter: Which species? Characteristics? Main sources in food? Symptoms in humans? Incubation? At risk groups?
Campylobacter jejuni and coli:
- gram negative spiral rods
- microaerophilic and slightly thermophilic (41-42C)
Most common worldwide cause of human bacterial gastroenteritis
Main sources:
- POULTRY meat (persists well in the caeca)
- also red meat and water
Incubation: 1-10 days (usually 2-5)
Symptoms (last 3-6 days usually):
- gastroenteritis: diarrhoea (frequently with blood) and vomiting
- abdominal pain
- headache
- fever
- sometimes invasive septicaemia
- CNS based sequelae
Main at risk groups?
- <5
- > 65
- bowel cancer patients
- those taking proton pump inhibitor drugs (increases gastric pH)
Complications of Campylobacter in humans?
Bacteraemia Hepatitis Pancreatitis Miscarriage Post-infection complications: - reactive arthritis - neurological disorders such as Guillain-Barré syndrome (polio-like form of paralysis that can result in respiratory and severe neurological dysfunction or death in a small number of cases)
What increases cross-contamination of Campylobacter during slaughter process?
Automated plucking, evisceration and scald and wash tanks - process up to 200 birds per minute
FSA targets for Campylobacter contamination?
Main FSA target is to reduce contamination of carcasses >1000 cfu/g
Secondary target is to reduce lower level contamination
No current targets for liver or deep muscle contamination which appear to be increasing
Which E.coli pathotypes are associated with enteric infections of humans?
EPEC = Entero Pathogenic E. coli (Childhood diarrheoa) ETEC = Entero Toxigenic (Travellers diarrhoea) EIEC = Entero Invasive EHEC = Entero Haemorrhagic (STEC/VTEC) EAEC = Entero Aggregative (persistent diarrhoea - increasingly food associated)
Prevalence of E.coli shedding by UK cattle? Main site of colonisation in animals?
5%
Distal rectum - requires LEE T3SS to colonise
E.coli EHEC in food: Sources?
Sources:
- often poorly cooked ground/minced beef (hamburger disease) or cross contamination of cooked meats from raw infected meat
When may Clostridium difficile cause diarrhoea?
Usually part of normal gut flora
May cause diarrhoea following antimicrobials or chemotherapy - disruption of normal flora (major problem in hospitals)
Norovirus: What is it? What does it cause? Symptoms?
ssRNA calicivirus
Highly infectious-main
‘Winter Vomiting Bug’
Largest cause of diarrheoal disease in UK
Associated with outbreaks in schools, hospitals, nurseries, cruise ships etc. (and hotels hosting Veterinary conferences)
Symptoms:
- fevers
- headache
- abdominal pain
- vomiting and diarrhoea
Most cases through person-to-person transmission but around 70,000 foodborne cases each yea
Hepatitis A: What is it? Source? Transmission?
ssRNA picornavirus that is excreted in high amounts in faeces of infected humans (up to 108 infectious doses/g) Now rare in UK Transmission: - person-to-person (poor hygiene) - anal intercourse - faecal contamination of food and water Some protection through passive (Ig) or active vaccination High risk groups include sewage workers
Foodborne hepatitis A:
- main source is contaminated shellfish (oysters in particular)
- virus replicates in GI tract, migrates to liver causing cell damage
- symptoms include nausea, diarrhoea, vomiting, jaundice and ‘flu-like’ illness
Hepatitis E (HEV): What does it cause? Source?
Usually causes a short-lived, self-limiting hepatitis but can lead to severe disease and death
Pigs considered likely source
