Food-borne Diseases and Food-borne Safety Flashcards
Why should vets be a part of food-borne safety?
* 11,000 people suffer food poisoning in AUS everyday
* Many of the infectious agents involved in food poisoning come from animals
* Management systems can be used to limit the presence and proliferation of organisms in food (food is not sterile)
* Many of the undesired contaminants of food “enter” the food chain at points which can be influenced by veterinarians (use of antibiotics, drugs, farm chemicals)
What parts of the production line do vets have a say with meat?
What is HACCP?
Hazard Analysis Critical Control Point
* Science based system of identifying, evaluating and controlling hazards which are significant for food safety
* Important: Based on prevention!
What are the 7 principles of HACCP?
- Hazard Analysis
- Identify Critical Control Points
- Establish Critical Limits
- Monitor the Critical Control Points
- Establish Corrective Action
- Record Keeping
- Verification
What is hazard analysis? Example?
* ID hazards (bio, chemical, or physical) that effect food quality or safety
*ID where in the production process the hazards arise (flow chart)
* ID preventive methods
Example: Antibiotic residues in meat products due to allergies and resistance.
Arises: on farm
Prevention: stop using OR appropriate and safe use of antibiotics (proper periods before meat sell)
What is the step “Identify Critical Control Points?” Where are the CCPs in a slaughter house?
* Steps at which control can be applied and food safety hazard can be prevented, eliminated, or reduced to an acceptable level.
e.g. Antibiotic use and appropriate time before selling meat (with holding periods)
** CCPs: meat inspection and chilling (important for reducing microbial contamination)
What is meant by establish critical limits?
* Establish the operational boundaries of teh CCP ( the parameter you will measure to ensure that CCP is under control)
e.g. antibiotics- presence: yes or no
** Abattoir: chilling (time and temperature– 4C or below within 24 hours of slaughter), meat inspection (presence or absence of gross faecal contamination, milk, hair– “zero tolerance” for any gross contamination of the meat product))
What is meant by “monitor the CCPs?” How is this accomplished in an abattoir?
* Monitoring is a planned sequence of measurements or observations to ensure the process at the CCP is under control
e.g. sheet filling out the treatment details and check the with holding period (WHP)
**Visual inspection at meat inspection AND the chilling checking the time and temperature
What is meant by “establish corrective action?” What would happen if the abattoir did not meet standards?
* Pre-plan what to do if monitoring indicates that there is a deviation from the critical limit
e.g. remove the animal or product from processing, ID and traceability is important for this
**Contaminated meat is trimmed and condemned, further training of staff, review inspection procedures, review infrastructure.
** Chilling: inadequately chilled meat could be removed, review chilling procedues, review equipment
What is meant by “record keeping?”
* preparation and maintenance of written HACCP plan
* will be audited
* all records generated during the monitoring of each CCP
* Records of any deviations from CL and the corrective actions taken
What is meant by “verification?”
* Verify that the HACCP plan is working
* Can involve the review of HACCP plans and records (audit) and also sampling and analysis
e.g. testing of meat for antimicrobial residues (maximum residue limits- MRLs)– national residue survey (NRS)
Where could contamination arise that vets are concerned with?
* Slaughter process (*evisceration*- removing GIT OR chest stick- risk of contaminating interior with microbes present on the skin OR when removing skins– same thing contamination from the skin)
* Dressing and processing of carcass
** mainly for vets
What are the possible agents that cause food-borne disease?
What is the ESAM program?
E. coli and Salmonella program
* Mandatory for all export abattoirs
* Set number of carcasses randomly selected for swabbing (e.g. 1 test per 1500 carcasses)
* Swabs sent to the laboratory for testing and bacterial enumeration
Why is it sometimes difficult to track food-borne outbreaks?
Often not notified
What are notifiable enteric diseases in VIC? Group A diseases?
What are notifiable enteric group B diseases in Victoria?
Food-borne diseases vs. zoonotic diseases
What are some common infectious agents of animals that cause food-borne disease in humans?
What are some common infectious causes of food-borne disease due to contamination (human food handlers, environment)?
What are some diseases due to toxins or chemicals present in food (natural toxins or contaminants from the environment)?
What are some common foods causing disease in undercooked or raw food?
Raw undercooked chicken- cross contamination mostly
What are high risk foods in the minced meat products category?
What is the third category of common foods causing disease?
What is the problem with aiming for 4 C refrigeration?
Listeria- especially when you are eating it cold
What are some of the symptoms of food-borne disease in humans?
What are some potential chronic sequelae after serious food-borne disease?
What are “at risk” people for food- borne disease? Who? Where?
Why are developing countries more susceptible for food-borne disease?
* **unsafe water, cold chain lacking, lack of education, lack of health care system, etc.
With Salmonella numbers on the rise, what might be to blame?
* Salmonella Enteriditis not endemic in AUS egg layers (common overseas and major cause of egg related outbreaks)
* Infection of egg contents via trans-ovarian transmission is the most common route for Salmonella Enteritidis
* Most egg related in AUS due to S. Typhimurium- much lower potential for transovarian transmission
* outbreaks in AUS- contaminated surface of egg shell a likely source of Salmonella for many outbreaks
Why is it difficult to track Samonellosis associated with eggs?
How do you prevent disease from Salmonella in eggs?
(eggs can be pasteurized in their shells- not yet introduced in Australia– no different to normal raw eggs but have been pasteurized)
How can you controll Salmonella in eggs on-farm?
Name 3 enteric diseases from Group A and 3 Group B diseases that are notifiable in Victoria
Who is required to notify to the department of health?
Laboratories and health care professionals
The picture: every case means that many more are out there
What does surveillance allow us to do with food and water borne illness?
What are the main modes of transmission? What are the main foodborne pathogens?
What are point source outbreaks? How is the department of health notified?
What are cluster investigations?
Often spread over a geographic area (across Australia for example)
What are the three parts of how outbreaks are investigated?
What is the initial response to a food or water borne outbreak?
When is a cohort study used?
Point source outbreak
When do you use a case control study?
Cluster investigation
What is a confidence interval? P value? What does statistical significance depend on?
What are the types of bias and how is it handled in a food or water borne outbreak?
What are potential outcomes of outbreaks?
Why are eggs such a big problem for Salmonella outbreaks?
What are the limitations to egg outbreak investigations?
What are the main serotypes of Salmonella causing Salmonellosis from eggs in Victoria?
How are eggs contaminated?
What are specific problems with Salmonella and chickens?
