Restaurant-associated Typhoid Fever Outbreak in Taoyuan, Taiwan, 2015

Restaurant-associated Typhoid Fever Outbreak in Taoyuan, Taiwan, 2015

In March and November 2015, three indigenous typhoid fever cases emerged in Longtan, Taoyuan, and the obtained isolates, Salmonella enterica serovar Typhi, shared a common pulsed-field gel electrophoresis (PFGE) pattern, SIX.001. Epidemiological investigation revealed six restaurants as the suspected sources of infection. Stool cultures from two asymptomatic food handlers at restaurant A yielded S. Typhi. Both of them tested negative in March, 2015. Reviewing Taiwan PulseNet for isolates associated with outbreak cases, the PFGE profiles of these two isolates were indistinguishable from the two cases occurred in November 2012, who also resided in Longtan District and visited restaurant A before onset. By multiple-locus variable number tandem repeat analysis (MLVA), isolates associated with this outbreak can be discerned from other SIX.001 isolates which frequently recovered from Indonesian migrant workers in Taiwan. No further cases occurred after the closure of restaurant A. Based on the evidence of molecular epidemiology and case investigation, we successfully controlled the outbreak.