Pre-Harvest Food Safety Flashcards
What is the definition of a zoonosis?
Diseases which are transmitted between vertebrate animals and humans
What is the definition of a carrier?
Pathogens isolated from animal/human without causing clinical signs of disease in the host
What is a colonised host?
No clinical signs on host but implies that microbes multiply on the host
What is a reservoir of disease?
The spread of an organism within the reservoir host to maintain the pathogen indefinitely
What are the clinically relevant multidrug-resistant pathogens?
Enterococcus faeciumStaphylococcus aureusKlebsiella penumoniaAcinetobacter baumanniiPseudomonas aeruginosaEnterobacter species
Give some examples of zoonoses in companion animal practice
RabiesSalmonellosisBrucellosisMR bacterial pathogensTuberculosisWormsPasteurellosisToxoplasmosisLeptospirosisPsittacosisFleasCheyletielliosisSarcoptic mangeDermatophytosis
What are the three types of MRSA?
Human hospital-associatedCommunity-associatedLivestock-associated
What do MRSA have resistance to?
Broad beta-lactam and often fluoroquinolone resistance
What does MRSA stand for?
Meticillin resistant Staphylococcus aureus
Where does S. aureusnormally live?
Human nose - opportunistic pathogen
What things can result from an MRSA infection?
Extended length of stay in hospitalLimited treatment optionsIncreased costIncreased mortality (though not proven)
What are the implications for MRSA in small animal practice?
Most infections can be treated successfullyCan be transmitted between pets and humans in both directionsPrimarily a human-hospital pathogen therefore higher risk of human infectionOwner perceptions may vary
What are the two main zoonoses linked with exotic pets?
Reptile related salmonellosisFish tank granuloma (Mycobacterium marinum)
What is the first key responsibility in zoonoses detection?
Early suspicion and correct diagnosis
What three things can alert us to the possibility of zoonoses?
HistoryClinical presentationPathogens present
Why should we alert clients to potential zoonoses?
Risk of transmission - part of our professional conduct
Which owners are more at risk from contracting zoonoses?
Compromised host susceptibilityClose contactVery young or elderlyRisk factors - wounds, cuts, bites etc.
What should we recommend clients to do if their pet is suspected of having a zoonosis?
Refer to GP/practitioner
What four thigns can we do to help prevent spread of zoonoses?
Manage the patientPractice hygieneKeep personal hygieneUse antimicrobials responsibly
When should you change your apron in practice?
Between every patient
What is the survival time for bacteria on dry surfaces?
Gram +ve: many monthsGram -ve: many monthsPseudomonas aeruginosa: 5 weeks on dry, 16 months on wetSpore-forming: many months
What are the three stages of traffic-light isolation protocol?
Red - isolated unless clinically unstableAmber - barrier nuse in wards/ICU to await microbiology/virology examinationGreen - patient can be nursed in wards - no isolation required
What are the visiting requirements for isolation?
Clinican arranges and informs receptionDesignated personnel for duration of visitClient must have protocols explainedClient must sign ‘Form of Agreement’Must wear full isolation protective clothingMust be supervised at all timesMust follow hand-washing protocolsVisit and communication recorded on CRIS
Describe infection control with a patient with a known zoonotic infection
Patient should wait outsideSeen at end of the dayDisinfection before next patientIsolation of patients and barrier nursingMove within surgery on trolley or in basketSpecial care in procedure areas
What is disinfection no substitute for?
Cleaning - decreases pathogen burden 90%
What is the BSAVA responsible use of antimicrobials?
Practic policyReduce prophylaxisOther optionsTypes of bacteria and drugsEmplying the correct antibacterialCytology and cultureTreating effectively
What are the five factors for emergence of zoonoses?
Environmental changesHuman and animal demographyPathogen changesChanges in farming practicesSocial and cultural factors
What proportion of emerging infectious diseases are zoonotic?
75%
What are endemic zoonoses?
Zoonoses that are constantly present in a certain population
What are some examples of neglected endemic zoonoses?
AnthraxBrucellosisBovine TBCysticercosis & neurocysticercosisHydatid diseaseRabiesHuman African Trypanosomyasis
What is the proportion of zoonotic pathogens in humans?
60%
What is the difference between a notifiable disease and a reportable disease?
Notifiable disease need to report a suspicion of a clinical case of diseaseReportable disease needs to be made by laboratory which isolated organism from a sample
What are the zoonoses that need to be reported in farms/veterinary practices?
AnthraxAvian influenzaBovine tuberculosisBSEBrucellosisCampylobacteriosisCryptosporidiosisE. coli O157Verotoxigenic E. coliErisipeloidGiardiosis
Which zoonoses are non-notifiable in farms and veterinary practices?
Resistant bacteriaLeptospirosisLouping illNewcastle diseaseOrfToxoplasma gondiiTrychophytumsppSalmonellosis
What are the main sources of zoonotic resistance?
EnvironmentProduction animalsHumansVeterinariansDogs and catsWildlifeHospitalsMeat, eggs and milk
Which bacteria is the emergence of resistance a major issue?
Gram negatives
Which two zoonoses are common but not reportable?
Orf: highly contagious viral infection most commonly seen after lambingRingworm:fungal infection - itchy, raised patches that tend to have sharply defined edges
Define a risk
Probability of occurrence and consequences
What are the three elements in risk analysis?
Risk assessmentRisk managementRisk communication
What are the two objectives of risk analysis?
Priority settingSelection of prevention strategies
What things should be used to determine the probability of infection with zoonoses?
Evidence of prevalence of hazard in target populationInformation about biology of the hazard
What things should be done to prevent and control zoonoses on farms?
Assess risks to health from work activites that involve a hazardous substancePrevent or control exposure to hazardous substancesIntroduce and maintain control measuresRegularly review risk assessments and effectiveness
Who are the risk groups of visitors at farms?
Young childrenElderly peopleImmunocompromised individualsPregnant women
What should be implemented in healthy animals to help prevent and control zoonoses on farms?
Vaccinate and worming programmesAvoid contaminating drinking waterRoutine health checksImplement a Herd Health PlanGood animal husbandry and management practiceImpelement biosecurity
What should be promoted when trying to prevent and control zoonoses in farms?
Use of protective equipment especially when dealing with sick animals
For what reasons are zoonoses under-reported?
Lack of awarenessSub-clinical infectionClinical signs are minor and not perceived to require medical attentionNegative impact
When does the veterinarian become part of the food production chain?
When animals are raised for food production - keep the public healthy
Define a hazard
An agent, substance or action that has the potential to cause an undesired event
What is the definition of a risk?
The probability of an undesired event and the consequences of an undesired event
What four things are values at risk in the food chain?
Food SafetyAnimal HealthAnimal WelfareEnvironment
What is the objective of risk assessment at the farm level?
Identify relevant hazards, prioritise them and to evaluate risk management strategies
What is the objective of risk management?
Reduce or prevent the risk related to a hazard
What is the goal of preharvest food safety?
Minimize the risk of foodborne illness
Where can hazards originate from and how can transmission occur?
Originate from many sources and transmit via direct or indirect pathways
What should vets be familiar with in relation to hazards?
That they can originate from many sources and be familiar with the biology of the most relevant food hazards even if they don’t cause disease in animals
What are the three types of hazards in animal-derived foods?
BiologicalChemicalPhysical
What are the four main processes on a farm where risks occur?
Feeding practices and production of animal feedVeterinary treatmentsEnvironmental hazardsInadequate hygiene
What are the five sources of food-safety hazards at pre-harvest and two examples of each?
Animal - Salmonella and TBPersonnel- Salmonella and S. aureusWildlife - Salmonella and TBEnvironment - Campylobacter and Coxiella burnettiFeed - Salmonella and Listeria
What can feed and water be contaminated with?
Different chemical and biological hazards
What is the responsibility of manufacturers in feed production?
Safety of feed sold to farmers as ready to be given to the animals
When are farmers responsible for the safety of their feed?
Those who source ingredients to produce their own feed
What two aspects of animal husbandry need to be managed for risks and hazards?
Introduction of hazards into the farmSpread of pathogens within a farm
What do specific husbandry practices influence?
The likelihood of introduction of hazards into the farm
What do improvements in animal welfare have the potential to reduce?
On-farm risks to food safety, principally through reduced stress-induced immunosuppression, reduced incidence of infectious disease on farms and reduced shedding of human pathogens by farm animals, and through reduced antibiotic use and antibiotic resistance
What are the three control programs used to control Salmonellaon farms?
Poultry sector:programs in breeding chicken flocks, laying flocks, broiler flocks and breeding and fattening turkey flocksPigs:UK ZNCP - reduction of the risk to consumersOther species:passive surveillance
What is an incident?
The first isolation and all subsequent isolations of the same serovar from an animal usually within a 30 day period
What is the most commonly reported zoonosis in the EU?
Campylobacter
What species is Campylobactercommon in?
Poultry and livestock
What is the aim of the FSA campylobacter risk management program?
Reduce levels of Campylobacterin chicken targeting different points along the food chain
What are the on-farm interventions for Campylobacterrisks?
BiosecurityFeed and water additivesReduce risk of colonization, vaccination and genetic resistance
What are the three routes of human infection with E. coli O157?
Consumption of contaminated food or waterDirect contact with animals or their faecesPerson-to-person spread
What is the main reservoir ofE. coliin the UK?
Cattle - other ruminants can be infected
Why is the risk to the public from TB very low?
Milk is pasteurised and their is a very effective TB surveillance and control programme in cattle
What is the risk pathway?
Sequence of events or actions that can lead to outcomes happening - can be basis for risk management
What are four key examples of foodborne pathogens that may contaminate food products at farm level?
SalmonellaCampylobacterE. coli O157TB
What is risk management?
Strategies and interventions aimed at risk reduction or elimination
What is risk management based on?
Risk assessment
What is risk management targeted at?
Interrupting, preventing or eliminating transmission pathways identified in risk assessment
What three things does risk management include?
Identifying the most cost-effective management optionImplementationMonitoring and follow-up
What is critical for effective risk management by clients?
Risk communication
What are the four risk management strategies?
Risk transferRisk avoidanceRisk mitigation or reductionRisk acceptance
What is risk transfer?
Insuring against events
What is risk avoidance?
Not performing an activity that is hazardous e.g. change in business
What is risk mitigation/reduction?
Reduction of negative consequences to target levels
What is risk acceptance?
Keeping risks below an acceptable levelIf they are below a defined level then nothing should be done
What is the two-tiered approach to risk management in primary production?
First tier:pre-requisite program of generic practicesSecond tier: pathogen specific practices and technologies
What purchase policies can be implemented as a risk management strategy?
Quality standards on purchases within the production chainHealth certificates for animalsQuality certificates for feed
How can biosecurity be implemented in risk management strategies?
Aimed at preventing pathogens and toxins from coming in contact with the animals
What are the three sources of feed that need to be managed for risks?
On-farm productionPurchasedStorage
How can water be managed for risks?
Fence off polluted waterProtect water from contaminationMonitor water of on-farm wells
How should veterinary drugs be risk managed?
Prescribe according to prudent use guidelinesObserve specific legislation for food animalsObserve withdrawal periodsObserve recording requirementsSafely store and dispose of veterinary drugs
What are the statutory programs for managing risks associated with TB?
Test and killRestrict movementsBiosecurityVaccination?
What are the statutory programs for managing risks associated with BSE?
Test and removeFeeding banRemove specific risk material at slaughter
What are the statutory programs for managing risks with Salmonella?
Test and kill
What are the two elements in tracing animals and their products?
Animal identificationTracing
What five things should be done when preparing animals for slaughter?
Avoid stressPrevent soiling of animalsAssure animal is fit for slaughterAssure animal is fit for transportAssure animal identification
Why is it important to reduce stress when slaughtering animals?
Can activate shedding of pathogens such as Salmonellaor Campylobacter
Define monitoring
Continuous effort to collect data to detect changes or trends in the occurrence of disease in order to inform decisions
Define surveillance
A special case of monitoring where data are used to assess a status in response to a pre-defined threshold
What may the threshold level be for some hazards?
Zero
What are herd health planning programs?
Surveillance programs
What is the initial objective for surveillance programs?
Measure the general level of occurrence of the disease - monitoring
When do control programs start?
If the disease is considered to be important and action should be taken
When does monitoring become surveillance?
When cases are detected above a certain threshold and actions are then taken
What should hopefully occur during surveillance with control programmes?
Incidence decreases - surveillance used to assess the effectiveness of the control program
What should the objective of surveillance change to if eradication is achieved?
Demonstrating freedom from infection
What is the main definition of surveillance from the ECDC?
Series of activities to take action for prevention and control diseases
What eight things are characteristics of surveillance systems?
ObjectivesHazard selectionCase definition and diagnostic methodsTarget populationTiming and sampling intervalsData management and analysisMethods for data analysisFeedback and dissemination of results
What five things are elements of the design of surveillance systems?
Hazard selectionCase definition and diagnostic methodsTarget populationTiming and sample intervalsData management and analysis
Describe farm level surveillance systems
Emphasize diseases that are controllable by the individual farmerFocus on productivityRely on farm recordsFeedback to the farmer and actions discussed
What are the main monitoring/surveillance objectives for animal health?
National: Demonstrate freedom from diseaseOutbreak detectionIndustry: Monitor production diseasesMonitor zoonoses and food-borne pathogensProducer: Monitor production diseasesWildlife: Establish disease status
What are the main objectives for monitoring and surveillance in relation to food safety?
National: Progress of hazard reduction programmesIndustry: Assure freedom from hazardProducer: Assure freedom from hazard
What is a case definition?
An animal or unit that fulfils the specific definition based on clinical, laboratory or epidemiological characterisitics
What is an outbreak?
Cases clustered in time and space occurring at a higher level than expected
What is an epidemic?
Occurrence of more cases of disease than expected in a given area or among a specific group of people over a particular period of time
What is the difference between incidence and prevalence?
Incidence:rate (number of new cases/(population at risk*time at risk))Prevalence:proportion (number of existing cases/population at risk)
What is passive monitoring and surveillance?
WaitingCase reportingDependent on motivation and awareness
What is active monitoring and surveillance?
SearchingSurveysTesting
Define bias
Systematic error due to design, the implementation or the analysis of the surveillance program
Define random error
Error due to sampling variation
What are the three ways bias can occur?
Case detectionSelection biasInformation bias
How can selection bias occur?
Voluntary participationNot all farms listed in sampling frame
What are the four areas that the legal framework for inspections and controls mainly focus on?
Feed safetyAnimal identificationMedicine useWelfare
Who is responsible for reporting notifiable diseases?
Every veterinarian, animal owner and laboratory
What is the difference between notifiable and reportable diseases?
Notifiable - statutory requirement to report suspicion of a clinical caseReportable - statutory requirement to report laboratory confirmed isolation of organisms
What has to be precisely defined during surveillance?
What is a case?
What may be required when identifying cases?
Laboratory tests
What four things are we protecting by carrying out disease surveillance?
Public healthAnimal health and welfareEnvironment and wider societyInternational trade
What are the three main elements of disease surveillance?
Monitor trends in existing diseases in the UK by comparison against a thresholdMonitor and identigy potential new and emerging diseases, zoonotic infections and intoxicationsInform DEFRA and other stakeholders
Who carries out veterinary disease surveillance in the UK?
Animal owner/keeperVeterinary practicesLivestock Industry OrganisationsUniversitiesAbattoirsDiagnostic laboratoriesVMDInternational disease monitoring
What are the three diagnostic services that vets provide in practice?
Post mortem of carcass suitable for surveillancePostal samplesAdvice on disease diagnosis and control
What are the uses for submission of a carcass for PM examination?
Detections of:Endemic disease levelAnimal welfare issuesNotifiable diseasesNovel diseasesZoonosesChemical threat to the food chainAntibiotic resistanceAdverse reactions
What is used to standardise data collection in scanning surveillance?
Submission forms and the Farmfile database
What should be done if a diagnosis is not reached?
Quarterly and annual trend analysesMonitor the change in percent of diagnosis not reached for each body system/syndromeCompare with mean of previous 4 yearsAnalyse and interpretInform and act if appropriate
What is targeted surveillance?
Scientific research into new diseases or changes in recognised diseases identified by scanning results sometimes in a more active approach
What things do we use targeted surveillance for?
Notifiable diseasesZoonotic diseasesNovel diseasesAntimicrobial resistanceImport testing
What four things does national veterinary disease surveillance data originate from?
Scanning surveillanceTargeted surveillanceMandatory reportingVoluntary reporting
What is the role of the veterinary investigation centres?
Safeguard public and animal health, animal welfare, international trade and the environmentProvides standardised, quality assured dataAnalyses and interprets this dataInforms the stakeholders incl. DEFRA to allow for actionDiagnostic support for practitioners by carrying out subsidised post mortem examinations and laboratory testsAdvisory function to practising veterinarians
