title: Outbreak of Salmonella Braenderup infection originating in boxed lunches in Japan in 2008.
abstract: There have been only 2 reports of a large-scale foodborne outbreak arising from Salmonella enterica serotype Braenderup infection worldwide. On August 9, 2008, an outbreak originating in boxed lunches occurred in Okayama, Japan. We conducted a cohort study of 786 people who received boxed lunches from a particular catering company and collected 644 questionnaires (response rate:82%). Cases were defined as those presenting with diarrhea (≧4 times in 24h) or fever (≧38℃) between 12 am on August 8 and 12 am on August 14. We identified 176 cases (women/men:39/137);younger children (aged＜10 years) appeared to more frequently suffer severe symptoms. Three food items were significantly associated with higher risk of illness;tamagotoji (soft egg with mixed vegetables and meat) (relative risk (RR):11.74, 95% confidence interval (CI):2.98-46.24), pork cooked in soy sauce (RR:3.17, 95% CI:1.24-8.10), and vinegared food (RR:4.13, 95% CI:1.60-10.63). Among them, only the RR of tamagotoji was higher when we employed a stricter case definition. Salmonella Braenderup was isolated from 5 of 9 sampled cases and 6 food handlers. It is likely that unpasteurized liquid eggs contaminated by Salmonella Braenderup and used in tamagotoji caused this outbreak.
authors.affiliation: Okayama City Public Health Center, Okayama 700-8546, Japan. mizoguchi.yoshinori@gmail.com
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Mizoguchi
authors.forename: Etsuji
authors.initials: E
authors.lastname: Suzuki
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tsuchida
authors.forename: Toshihide
authors.initials: T
authors.lastname: Tsuda
authors.forename: Eiji
authors.initials: E
authors.lastname: Yamamoto
authors.forename: Katsumi
authors.initials: K
authors.lastname: Nakase
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Doi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004196:Disease Outbreaks; D004531:Eggs / Q000382:microbiology; D005260:Female; D005511:Food Handling; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012478:Salmonella Food Poisoning / Q000453:epidemiology* / Q000209:etiology; D013997:Time Factors