Food Poisoning Outbreak in Employees of Pathumthani Government Agencies in Phitsanulok Province, Thailand, 5 - 6 July 2013

Abstract

Background: At 9 A.M. on July 6^th, 2013. Phitsanulok Provincial Health Office received the notification by call from Social Medicine Department, Buddhachinaraj Hospital, Phitsanulok according to clusters of acute diarrhea were treating at emergency room. All cases are government officers from Pathumthani Province. On July 5^th, 2013, they had dinner at the hotel in Phitsanulok Province and then they developed symptoms such as diarrhea, and abdominal pain. Therefore, the SRRT team started outbreak investigate which aims to identify the causes of outbreak and implement control measures of food poisoning during July 6^th – 12^th , 2013.
Methods: 1) Descriptive study was conducted in this study and collected data form patients who were treatment at hospital. The aim of this study was to verify the patient characteristics such as, onset of symptoms, got treatment and discovered new cases. Definition of patient refer to an employee’s office from Pathumtani Province Who checked in at the hotel in Phitsanulok Province and their showed either symptom diarrhea, abdominal pain, nausea, vomiting, or fever during July 5-6, 2013. 2) Analytic Epidemiology was conducted the retrospective study to search the cause of diarrhea. 3) To investigate the hospital’s environment such as, dining room, restroom, operating water system, and kitchen. And 4) Collecting specimen to laboratory room such as stool of patients and businessman, the examination of patient whose contaminate from foods, plates and kitchen utensil.
Results: The patient of diarrhea about 86 of 107 cases (80.37%) was divided by gender composed of male that incidence rate 78.46; (51/65), and female that incidence rate 83.33; (35/42). The median age of patient was 48 years (Range 24 – 59 year). The ratio of gender between male and female was 1.46 : 1 (51 : 35). The duration time of patient start eating have lunch at office from Pathumtani Province until the onset of first symptom showed the median time was 10 hours and 30 minutes, the incubation period of maximum and minimum disease were 25 hours and 3.30 hours, respectively. The most symptom of patients composed of Watery (96.51%), weakness (54.65%), abdominal pain (54.65%), fever (39.53%), and Diarrhea (36.05%), respectively.
The result of statistic analysis (99% CI) found that there is the menu of lunch in July 5, 2013 is the food types were cause of disease such as, stir-fried mixed vegetables and shrimp, and crisp-fried fish. The results from laboratory room examination found Vibrio parahaemolyticus from stool of 16 patients, but not found this virus in businessman. Either the examination of patient whose contaminate from foods or plates found the coliform bacteria in knife and chopping block. Beside, considering the patient symptoms, incubation period, and microbiology showed that the cause of this diarrhea is Vibrio parahaemolyticus from food contaminate compose of stir-fried mixed vegetables and shrimp which the shrimp was cooked in the morning and served to participants at lunch.
Discussion and Conclusions: Risk factors for the food poisoning outbreak, found two types of risk factors, including stir-fried vegetables shrimp and Dried fish fry and the results of laboratory tests found bacteria that are pathogenic Vibrio parahaemolyticus. And a list of the risk factors and components of seafood, the investigation team to focus on food items. "Fried Shrimp" is the main cause of diseases. Outbreak of food poisoning is caused by an infection in the Bacteria Vibrio parahaemolyticus. That are contaminated with bacteria (shrimp) with preparation and cooking in the morning and eat lunch. The food was the cause of the disease was Fried Shrimp with Vegetables.