Scombroid Food Poisoning in Frozen seafood factory, Samutprakarn Province, 21– 25 July 2007

1. Scombroid Food Poisoning in Frozen seafood factory,Samutprakarn Province, 21– 25 July 2007 Nalinee Hongchumpon, DVM. 1st year FETP trainee

2. Introduction to Scombroid (Histamine) poisoning • Consumption foods that contain high level of histamine and other vasoactive amines and compounds • Eating spoiled fish of families Scombridae and Scomberesocidae • Tuna • Mackerel • Sardine • Histamine formed by histidine decarboxylating enzyme • Histidine decarboxylase producing bacteria : • Proteus morganii • Enterobactor aerogenes

3. Skipjack tuna Yellowfin tuna

4. Mackerel Sardine

5. Introduction to Scombroid (Histamine) poisoning • Symptoms very rapidly : burning sensation in the mouth, rash on upper body, drop in blood pressure, nausea, vomiting and diarrhea • Incubation period : 30 minutes after consumption (long last several days) • Histamine level (US FDA) : • Flesh fish ≤ 100 ppm. • Hazardous level ≥ 200 ppm

6. Background BoE received report from Samutprakarn provincial health office on 24th July 2007 Food poisoning outbreak among employees in frozen seafood factory in Samutprakarn province on 21st July 2007 BoE sent investigation team during 24th – 25th July 2007

7. Objective • To confirm diagnosis and outbreak • To define etiologic agent and cause of the outbreak • To implement control and prevention measure

8. Methodology • Descriptive study • Interviewed the patients who had been admitted in the hospitals • Interviewed staffs who worked in the frozen seafood factory • Active case finding • Analytic study • Case – control study • case : control = 1:2 • Structured questionnaires were used for collecting data

9. Methodology • Environmental survey • Interviewed food handler about process of cooking each lunch menu • Collected frozen tuna and fried fermented tuna the same lot as the patients ate on 21st July 2007, frozen mackerel and water samples for laboratory testing • Survey factory product line

10. Case definition • A case was defined as an employee who worked in the Frozen Seafood Factory S on 21st July 2007 and had symptoms as the criteria: • Criteria: Two major criteria or one major criterion plus two minor criteria • Major criteria: diarrhea, nausea, vomiting, flushing, abdominal cramp, mouth numbness, extremities numbness, dry mouth, rash, itchy and swelling • Minor criteria: headache, diplopia, fever and fatigue • Total number of cases: 89 persons

11. Control definition • Any persons who worked in the frozen seafood factory on 21st July 2007 and did not has the symptoms meeting the criteria as case • Selected by systemic random sampling: Every 4 persons by the listed name and skipped the person who was defined as case • Total number of control : 176 persons

12. Statistical analysis • Type of data • Categorical data : percentage of symptoms, each kind of food • Continuous data : Median for age • Software • Epi-data: To collect data • Stata: to analyze data

13. Results

14. Descriptive part • Seafood factory located at Muang district, Samutprakarn province • 100% seafood production export • 1,084 employees in 4 different section • All employees have lunch at cafeteria

15. Attack rate by section

16. Attack rate by food items

17. Number of patients by time of onset, seafood factory, Samutprakarn province, 21st July 2007 First group of having lunch Median ICP120 Minutes(IQR 60 – 180 minutes)

18. Percentage of each symptoms (n=89)

19. Analytic part

20. Univariated Analysis

21. Dose-response Chi – square for trend = 59.1 p – value < 0.00001

22. Environmental survey

23. Environment & Producing line • Divided into 4 sections >>> fish, shrimp, squid and back office • Employees have to take a bath and changed working suit before entering each section

24. Kitchen & Cafeteria • Kitchen and Cafeteria were in the same building but separated in each part • Food handler bought and cooked lunch day by day

25. Fermented Tuna cooked • Frozen tuna fermented with ingredient • Left in room temperature for a few day • Fried before serving as lunch • Water supply • Drinking water • Producing line

26. Frozen tuna Fried fermented tuna

27. Laboratory result

28. Discussion • Scombroid food poisoning outbreak • Previous case in Thailand • Reported case in other country • Histamine level, Fish family, Time, Temperature, Bacteria • Association between case and risk factor

29. Limitations • Most of patients got mild symptoms look like food allergy • Self recovery in 8-12 hours • Misclassifications • No reference laboratory to determine histamine level in human

30. Recommendations • Keep raw flesh fish ≤ 4 ํCprevents bacterial growth and formation of histidine decarboxylase enzyme • Frozen fish should not be exposed to temperature above 4 ํC for more than 12 hours • Histamine concentration periodically determined • In case of other food allergy, Physicains have to ask about history of eating seafood and the relations of patient group – eat from the same restuarant –

31. Conclusions • Scombroid food poisoning had occurred in seafood factory • Employees were eating fried fermented tuna which contain high level of histamine at lunch time 21st July 2007 • Common source outbreak

32. Acknowledgement • Seafood factory • Samutprakarn provincial health office • District and Sub district health office • Samutprakarn Hospital • Puttharaksa health center • Department of Fisheries • Department of Medical Science