1. Role of Laboratory in a Foodborne Outbreak Vietnam FETP Foodborne Outbreak Training Course Hanoi, Vietnam June 4, 2009

2. What are the goals of an outbreak investigation? Identify the source Identify the source Identify the risk factors Identify the risk factors Identify control activities Identify control activities

3. Physicians Physicians Surveillance system Surveillance system Media Media People who are sick People who are sick Who reports foodborne outbreaks?

4. Physicians Physicians Surveillance system Surveillance system Media Media People who are sick People who are sick Laboratory staff Laboratory staff Who reports foodborne outbreaks?

5. Role of laboratory in a foodborne outbreak Collect the right sample Collect the right sample Select the right test Select the right test Interpret the results Interpret the results Confirm cases Confirm cases –Go from probable to confirmed –Go from probable to not a case Work with others to understand the pathogen Work with others to understand the pathogen

6. Role of laboratory in a foodborne outbreak Member of outbreak field team Member of outbreak field team Included in planning the outbreak response Included in planning the outbreak response

7. Role of epidemiologist in a foodborne outbreak Talk to the laboratory as soon as possible

8. Special factors for testing food in an outbreak Epidemiologist helps lab test food Epidemiologist helps lab test food –Food testing requires an link to a case –Selective testing of food –Test for specific agents –Use food histories, onset of illness and symptoms to identify which pathogen to test for Collect clinical specimens as well as food samples and compare results Collect clinical specimens as well as food samples and compare results

9. Special condition for sample collection Timing Timing –Take samples from ill people as soon as possible and before they are given antibiotics –Have local staff collected suspected food as soon as possible

10. Outbreaks Involving Environmental Specimens Environmental specimens may be collected to confirm a source: food, water, fomites Environmental specimens may be collected to confirm a source: food, water, fomites –Food/water samples often collected in food or waterborne outbreaks –Frequently collected in conjunction with human clinical samples When clinical and environmental specimens yield same results, supports hypothesis that outbreak source is same as environmental specimen source When clinical and environmental specimens yield same results, supports hypothesis that outbreak source is same as environmental specimen source

11. Environmental Specimen Cholera A person in the US tested positive for cholera while hospitalized for diarrhea and dehydration A person in the US tested positive for cholera while hospitalized for diarrhea and dehydration –No common risk factors for cholera (raw shellfish, travel to endemic area) –Attended party 2 days prior to hospitalization; other attendees also experienced diarrhea, had laboratory evidence of cholera –Every person who was ill report eating homemade rice pudding prepared with frozen coconut milk imported from Thailand

12. Environmental Specimen Cholera A person in the US tested positive for cholera while hospitalized for diarrhea and dehydration A person in the US tested positive for cholera while hospitalized for diarrhea and dehydration –No common risk factors for cholera (raw shellfish, travel to endemic area) –Attended party 2 days prior to hospitalization; other attendees also experienced diarrhea, had laboratory evidence of cholera –Every person who was ill report eating homemade rice pudding prepared with frozen coconut milk imported from Thailand –Lab professionals cultured unopened packages of the same brand used to prepare the rice pudding –Tested positive for several types of Vibrio cholerae, Aeromonas, Salmonella