Pre-Harvest Food Risks Flashcards
Give examples of hazards at farm level
- e coli 0157
- Pesticides
- Water
- Salmonella
- low quality silage -> Listeria
Define hazard
agent substance or action that has the potential to cause an undesired event
Define risk
probablilty of an undesired event occourring and the consquences of the undesired event
Other than food safety what may risk assessment be used to manage?
animal health, welfare and economics
Give an example of practical application of risk assessment
BPEX (part of zoonoses national control programme ZNCP) online farm tool helps faremrs and vets develop farm specific salmonella control plans to refocus resouces away from standard salmonella sampling at abattoir level
What are the aims/objectives of risk assessment and risk management?
Risk assessment - identify and prioritise relevant hazards and evalutate risk management strategies
Management - reduce or prevent the risk related ot the hazard
What is the goal of preharvest food safety?
Minimise risk of food bourne illness
Give examples of latent zoonoses
- Salmonella
- E. COli 0157
- Campylobacter
> do not necessarily cause disease in animals
What are risk pathways? Give an eg. of a complex risk pathway
sequence of events that can lead to outcomes and can be the basis for prevenetion
- eg. cattle act as reservoir for shiga toxin producing E. COli, can be spread directly, via milk, water, underbooked minced meat, other foods or fomites
Give examples of hazards in animal-derived foods
> Biological (bacteria, virus, parasite)
Chemical (environmental contaminants, illegal substances, natural toxins (mycotoxins))
Physical (glass, metal, non-edible ingredients)
What are the 6 key foodborne disease pathogens prioritised by the FSA?
Highest - Campylobacter (^incidence, ^ severity)
- LIsteria monocytongnees (v incidence, ^ severity)
- E. Coli 0175 (v incidence, ^ severity)
- Salmonella (^incidence, ~severity)
- Norovirus (^incidence, v severity)
- CLostridium perfringens (v incidence, v severity)
Who is responsible for animal food and water safety?
Feed manufacturers (eg. dioxin in Irish pork) OR farmer is sourcing ingredients to produce their own food (eg. poor silage production -> listeria)
Give examples of hazards that have entered the food chain through food or water
- dioxin
- Pb
- Mycotoxin
- Salmonella
What are the main 2 serovars of salmonella that affect humans?
A. Enterica
S. Typhimurium
Why is farm level control of salmonella particularly important?
- can contaminate animla feed
- can affect eggs before they are fully formed
Which 2 species has salmonella control focussed on? How are other species treated wrt salmonella?
- Poultry (v effectice control programme, vax)
- Pigs (UK Zoonoses national control programme - reduction of risk but not as effective as poultry)
- Other species = passive surveillance
Define incident and incidents
> incident = first isolation and all subsequent isolations of the same serovar of salmonella from an animal or epidemiologically distninct group of animals occouring on a single premises within a 30d period
incidents = no of isolations (used in lieu of no. isolates as multiple isolats could be obtained from multiple samples taken in the same herd)
What is the most commonly reported zoonosis in the EU? What is the main source?
Campylobacter - most common cause of food poisoning
- broiler meat (65% samples chicken for salepositive for campylobacter) and untreated water, raw milk, raw meat
- endemic in many species (cattle, sheep pigs)
Outline the FSA campylobacter risk management programme
reduce % birds with high level infection from 26% - 10% by 2015
- on farm intervention inclues fly screens, feed and water addtives to v colonisation risk, vax, genetics
Give 3 routes of infection of humans with E coli 0157. WHat is the main reservoir for infection?
- consumption of contaminated food/water
- direct contact animals./feaces
- person-person spread
> main reservoir = cattle but other ruminants can be infected
What are the main risks with consuming raw milk?
- listeria
- E. Coli
getting fat1
Outline how the prevalence of TB has changed
- compulsory eradication since 1950
- levels decreasing, then incidence increased since 1980s
- last 10 years costs ^
How is TB testing rate decided?
In England split into nnual and 4 yearly testing regions based on county
In Scotland based on risk
How many humans are infected with mycobacterium avium paratuberculosis yearly? What does this say about the risk to public health?
<40
- risk to public health low due to pastuerisation
