Investigation of a salmonellosis outbreak linked to French toast sandwich with the use of surveillance camera, Taiwan, 2018

Abstract

Salmonella is a leading cause of foodborne outbreaks in Taiwan. On 27 April 2018, a salmonellosis outbreak among customers of a restaurant was reported to the Taiwan CDC. We investigated the outbreak to identify infection sources and prevent further transmission. We interviewed the ill customers and their dining companions. We conducted a case-control study to identify foods associated with the illness. Case-patients were those who had diarrhoea within 72 hours after eating at the restaurant during 16 27 April 2018. Specimens, food samples, and environmental samples were collected and tested for enteric pathogens. Salmonella isolates were analysed with pulse-field gel electrophoresis and whole-genome sequencing. We inspected the restaurant sanitation and reviewed kitchen surveillance camera recordings. We identified 47 case-patients, including one decedent. Compared with 44 controls, case-patients were more likely to have had a French toast sandwich (OR: 102.4; 95% CI: 18.7 952.3). Salmonella Enteritidis isolates from 16 case-patients shared an indistinguishable genotype. Camera recordings revealed eggshell contamination, long holding time at room temperature, and use of leftovers during implicated food preparation. Recommendations for restaurant egg-containing food preparation are to use pasteurized egg products and ensure a high enough cooking temperature and long enough cooking time to prevent Salmonella contamination.