1

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

nNo. of cases

No. of employees

Attack rate(%)

Fish 41 430 9.5

Shrimp

21 222 9.5

Squid

23 178 12.9

Back office

4 224 1.8

16

Attack rate by food itemsFood items

No. of cases

No. of eating

Attack rate(%)

Fermented tuna

88 193 45.6

Papaya salad

17 67 25.4

Gang Tai-pla

16 66 24.2

Gang kua 10 37 27.0

Bamboo soup

31 118 26.3

Fried kana 22 89 24.7

Fried bean 14 40 35.0

Plain rice 76 216 35.2

Fried rice 3 14 21.4

Drinking water

85 245 34.7

17

Number of patients by time of onset, seafood factory,

Samutprakarn province, 21st July 2007

0

5

10

15

20

25

30

Onset time(hrs/mins)

Number of patients

Median ICP 120 Minutes (IQR 60 – 180 minutes)

First groupof having lunch

18

Percentage of each symptoms (n=89)

24.7

25.8

27.0

37.1

46.1

53.9

58.4

59.6

59.6

71.9

0 10 20 30 40 50 60 70 80 90 100

rash

vomiting

mouth numbness

flushing

abd cramp

diarrhea

nausea

fatique

dry mouth

headache

19

Analytic part

20

Univariated Analysis

Risk factor

s

Case Control

OR95%C

IExpNon-exp

ExpNon-exp

Fermented tuna

88 1 105 71 59.59.8-

2409.1

Papaya salad 17 72 50 126 0.6 0.3-1.1

Gang Tai-pla

16 73 50 126 0.6 0.3-1.1

Gang kua

10 79 27 149 0.7 0.3-1.6

Bamboo soup

31 58 87 89 0.6 0.3-1.0

Fried kana

22 67 67 109 0.5 0.3-1.0

Fried bean

14 75 26 150 1.1 0.5-2.3

Plain rice

76 13 140 49 1.5 0.7-3.3

Fried rice

3 86 11 165 0.5 0.1-2.1

Drinking water

85 4 160 16 2.1 0.7-9.0

21

Dose-responsePieces Case Control OR 95%CI

0 1 71 1.0 -

< 2 24 50 34.15.1-

1420.4

2 -3 28 36 55.28.2-

2288.4

≥ 4 36 19 134.519.2-

5531.2Chi – 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

Specimens Histamine

level (ppm.)Bacterial culture

Fresh Tuna 3.92 Bacillus cereus Fried Fermented Tuna

446.18 Not found Enteropathogenic

Bacteria

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 ํC prevents 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