Pre-harvest food risks: What are they and how can they be managed? Flashcards
Define hazard
An agent, substance or action that has potential to cause an undesired event (e.g. Disease in consumer)
What are pre harvest risks?
Feed, housing, hygiene and treatments etc
Define risk
The probability of an undesired event and the consequences of an undesired event. Probability depends on hazard and process. Consequences depend on characteristics of hazard and target population
What values are at risk in a pre harvest risk analysis?
Food safety
Animal health
Animal welfare
Environment
What are the three components of a risk analysis?
Risk assessment, risk management and risk communication
Why is risk assessment central to decision making at farm level?
Food safety, animal health, production, welfare and economics
What is the objective of a risk assessment?
To identify relevant hazards, to prioritise them and evaluate risk management strategies
What is the objective of risk management?
To reduce or prevent the risk related to the hazard
What are latent zoonoses?
Salmonella, Campylobacter, E. coli 0157
What is the goal of pre harvest food safety?
To minimise the risk of foodbourne illness
What are the 2 components of pre-harvest stage?
farm production and farm inputs
Define HACCP
Hazard analysis and critical control point
What is the key concept of risk assessment?
risk pathway is the sequence of events or actions that can lead to outcomes happening and can be the basis for prevention.
Approximately what percentage of farm have some cattle with STEC?
> 20%
How do hazards arise and spread?
Originate from many sources and transmission can occur via direct or indirect pathways
What are 3 types of hazard found in animal-derived foods?
Biological, chemical and physical
Where can the hazards Campylobacter and Coxiella burnetti orginate?
Environment
What is the Foodbourne Disease Strategy 2014-15?
An FSA programme for reduction of foodbourne disease in UK.
What pathogens are priorities for FDS action?
- ) Campylobacter (high probability of occurrence although not a very severe infection)
- ) Listeria monocytogenes (low probability but high severity)
- ) E.coli 0157
- )Salmonella
- ) Norovirus
- ) Clostridium perfringens (more important at harvest and post-harvest stages)
Examples of things causing food and water contamination
Dioxin, Pb, mycotoxins and salmonella.
Origin of Dioisin in Irish pigs 2008 was the oil used in a drying machine at a company that recycles food into pig meal –> animal feed contaminated with dioxins supplied to cattle and pig farms –> recalls of animal products in 23 countries!
When does Listeria grow in silage?
When silage is of poor quality (i.e. pH is too high)
How does animal husbandry play a role in pre-harvest risks?
Introduction of hazards into a farm
Spread of pathogens within a farm
Animal welfare - consequences if compromised
Which salmonella serotypes account for 60-80% of all human salmonellosis?
S.enterica Typhimurim and Enteriditis
How prevalent is Salmonella in UK animal feed?
In GB, 2010, 0.9% samples from feedstuffs and ingredients were positive
How can eggs be contaminated with Salmonella?
Before the shell is formed
How is Salmonella controlled in poulty, pigs and other species?
Poultry - control programs
Pigs - UK Zoonosis National Control Program
Other species - passive surveillance
Over the years, cases of salmonellosis in Uk humans has significantly dropped which is indicative of a very successful control program.
Define incident
the first isolation and all subsequent isolations of the same serovar of a particular Salmonella from an animal or epidemiologically distinct group of animals occuring on a single premises, usually within a 30 day period.
Outline Campylobacter epidemiology
commonest reported EU zoonosis
commonest cause of UK food poisoning
4th commonest cause of US food poisoning
common in poultry and liverstock - broiler meat the main source for humans as FSA survey in 2007-8 indicated Campylobacter present in 65% of samples.
Endemic in animals (poultry, cattle, sheep, pigs)
Sources include food and non-food (e.g. untreated water). Found mainly in poultry but also red meat, raw milk and untreated water
Outline the FSA Campylobacter Risk Management Program
Aim - to reduce levels of Campylobacter in chicken targeting different points along food chain.
FSA, DEFRA, producers and retailers involved.
What are on-farm campylobacter interventions?
biosecurity (fly screens), feed and water additives, vaccination, genetic resistnace
Main UK reservoir of E.coli 0157 in UK is?
Cattle but other ruminants can be infected. Infected animals don’t normally show clinical signs.
Routes for human E.coli 0157 infection = ?
consumption of contaminated food/water
direct contact - animals or faeces
person to person spread.
e.g. Surrey Farm 2009, trendy raw milk
When did GB TB eradication program begin?
- Gradually reduced incidence to very low levels by early 1980s but since then, incidence has been increasing. Last ten years has cost government more than £500 million. Could cost another £1 billion in next ten years unless current trends are reversed.
How frequently is bTB testing carried out in Scotland?
It has a risk-based routine herd testing policy. THis targets testing at higher risk herds. Around 35% of herds are considered low risk and are exempt from routine testing. Herds that aren’t exempt are tested every 4 years.
What is the average yearly number of M.bovis isolates from humans (2005-2010)?
30-40
What are hazards during harvest?
Contamination from animals, people, environment, equipment. Consequences - spoilage, reduced shelf life, food-bourne infection or intoxication
What are risk management strategies and interventions aimed at?
Risk reduction or elimination. Based on risk assessment. IT is targeted at interrupting, preventing or eliminating transmission pathways identified in the assessment
What does risk management involve? 3
Identifying the most cost-effective management option
implementation
monitoring and follow-up
What is critical for effective risk management by clients?
risk communication
What are 4 risk management strategies?
- ) Risk transfer
- ) Risk avoidance
- ) Risk mitigation, risk reduction
- ) Risk acceptance
What can risk management strategies be structured in primary production?
A two tiered approach:
FIRST TIER: pre-requisite program of generic practices (purchase policies, biosecurity, good farming practice, good hygiene practice, farm management, feed, water, drugs)
SECOND TIER: pathogen specific practices and technologies (e.g. use of probiotics or vaccines to reduce risk of E.coli 0157 infection/shedding)
What section of management strategy is HACCP a part of?
good hygiene practice
What aspects of feed need attention? 3
on-farm production
purchased
storage
What aspects of water need attention?
Fence off polluted water
protect water from contamination
monitor water of on-farm wells (i.e. from unofficial supply)
What aspects of veterinary drugs need attention? 5
Prudent prescription Legislation Withdrawal periods Recording requirements Safe storage and disposal
Defien FCI
Food Chain Information
What is the vet/farmer responsibility relating to AMs?
VETERINARY - follow guidelines, cascade principles, correct labelling of packages left on farm, recording of purchases/sales/treatments
FARMER - record purchase/treatment, treatments are part of the FCI
Problems associated with antimicrobial residues…
AMR
allergies
problems with processing - e.g. cheese
Managing options for bTB
test-and-kill
movement restrictions
biosecurity
vaccination? (not cattle because serological interference)
Managing options for BSE
test-and-remove
feeding ban
removal of specific risk material at slaughter
Managing options for salmonella in poultry
test-and-kill
Managing options for on-farm milk harvest
Maintenance of milking equipment milking hygiene hygienic storage cooling quality monitoring
2 elements of traceability (increasingly important part of risk management)
Animal ID
Tracing
How should animals be prepared for slaughter? 5
Avoid stress prevent soiling of animals assure animal is fit for slaughter assure animal is fit for transport assure animal identification
Important for food safety, food quality and animal welfare.
What happens if animals are stressed at slaughter?
Can activate shedding of pathogens such as Campylobacter
Can animals without ID enter the food chain?
No
What is the Food Chain Information (FCI)?
A document that the farmer is responsible to provide for each animal that enters the meat chain. If has bee gradually introduced and is now fully implemented in all species (poultry, pigs, cattle and sheep). The document provides information on the producer, health status of animal and farm, treatments and vaccination. Slaughterhouse operators to ‘request, receive, check and act upon FCI –> may not enter meat chain
What official checks are farms subject to?
DAIRY - inspections by Animal Health on behalf of FSA, milk hygiene, equipment, animals, approval of premises.
ALL FARMS HOLDING FOOD ANIMALS - local authorities, animal ID, biosecurity, record keeping
QUALITY ASSURANCE SCHEMES - to increase consumer confidence, may be required by some retailers but not official.
