An Outbreak of Gastroenteritis due to Salmonella in a Secondary School, Phuket, Thailand - การระบาดของโรคลำไส้อักเสบจากเชื้อ Salmonella ในโรงเรียนมัธยมศึกษาแห่งหนึ่งในจังหวัดภุเก็ต

Abstract

Food borne disease outbreaks were commonly reported in developing countries. Children are
more effected with higher incidence and virulence than other groups. On December 7, 2011, there
were 14 gastroenteritis patients which were students and teachers from a secondary school. The
retrospective cohort study was immediately conducted in order to identify the cause and to control
this outbreak. Active case finding was done. Data was collected by direct interview methods. There
were a total of 218 cases; an attack rate was 10.34 percent. Abdominal pain and watery diarrhea
were prominent symptoms. The highest attack rate was found in grade 7, grade 10 students and
teachers which were assigned to have lunch at cafeteria A. Rice mixed with shrimp paste, a lunch
dish served at the cafeteria A on December 6 showed statistical significant association (risk ratio
16.16). Salmonella group D was identified in 12 samples of patients’ stool, 2 samples of food handler
s’ stool, and 5 food and environment samples. Many clues suggest that rice mixed with shrimp
paste was the source of this outbreak, even without supporting evidence of bacterial culture. General
and specific control measures were in place accordingly.
Key words: gastroenteritis, food poisoning, outbreak, Salmonella