An outbreak of gastroenteritis caused by Salmonella enterica serotype Enteritidis traced to cream cakes
10.2471/10.5365/wpsar.2010.1.1.001
- Author:
Solhan Suhana
;
Chan Pei Pei
;
Lalitha Kurupatham
;
Foong Bok Huay
;
Ooi Peng Lim
;
James Lyn
;
Phua Leslie
;
Tan Ai Ling
;
Koh Diana
;
Goh Kee Tai
- Publication Type:Journal Article
- From:
Western Pacific Surveillance and Response
2011;2(1):23-30
- CountryWHO-WPRO
- Language:English
-
Abstract:
Introduction:This paper describes the epidemiological, microbiological and environmental investigations conducted during an outbreak of Salmonella gastroenteritis in Singapore.
Methods:A case-control study was undertaken to identify the vehicle of transmission. Microbiological testing was performed on faecal, food and environmental samples. Isolates of Salmonella were further characterized by phage typing and ribotyping.
Results:There were 216 gastroenteritis cases reported from 20 November to 4 December 2007. The causative agent was identified as Salmonella enterica subspecies enterica serotype Enteritidis for 14 out of 20 cases tested. The vehicle of transmission was traced to cream cakes produced by a bakery and sold at its retail outlets ( P < 0.001, OR = 143.00, 95% Cl = 27.23–759.10). More than two-thirds of the 40 Salmonella strains isolated from hospitalized cases, food samples and asymptomatic food handlers were of phage type 1; the others reacted but did not conform to any phage type. The phage types correlated well with their unique antibiograms. The ribotype patterns of 22 selected isolates tested were highly similar, indicating genetic relatedness. The dendrogram of the strains from the outbreak showed distinct clustering and correlation compared to the non-outbreak strains, confirming a common source of infection.
Discussion:The cream cakes were likely contaminated by one of the ingredients used in the icing. Cross-contamination down the production line and subsequent storage of cakes at ambient temperatures for a prolonged period before consumption could have resulted in the outbreak.
