Salmonella Enteritidis Outbreak Linked to a Bakery in Kinmen, Taiwan, November 2016

DOI: 10.6525/TEB.201805_34(9).0001

Yen-I Lee1*, Tzu-Yi Lin2, Shan-Wei Hsu3, Lin-Ching Huang1, Wan-Ting Huang1, Ying-Shu Liao4, Chien-Shun Chiou4

2018 Vol.34 NO.9

Correspondence Author: Yen-I Lee1*

  • 1Office of Preventive Medicine, Centers for Disease Control,Ministry of Health and Welfare, Taiwan
  • 2Taipei Regional Center, Centers for Disease Control, Ministry of Health and Welfare, Taiwan
  • 3Public Health Bureau of Kinmen County Government, Taiwan
  • 4Center for Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taiwan


On November 25, 2016, over 70 people were reported having gastroenteritis after consuming products from Bakery A in Kinmen. We conducted an investigation to determine outbreak scale and infection source. We defined cases as patients visiting emergency department of Kinmen County Hospital during November 24–29 who met one of the designated ICD-10 codes (K52.9/R19.7/A09/R50.9) and consumed products from Bakery A within three days before illness onset. We interviewed cases, inspected Bakery A and collected leftovers and stool samples of cases and food handlers for enteropathogens testing and pulsed-field gel electrophoresis (PFGE) genotyping of isolates. Among 235 cases, 176 (75%) reported consuming mayonnaise-contained products, 28 (12%) consumed mayonnaise-free products, and 22 (9%) consumed both. Stools (n = 18), leftovers with/without mayonnaise (n = 20), workbench and bread knife (n = 2), all yielded Salmonella Enteritidis with identical PFGE patterns. Environmental investigations implicated possible cross-contamination by using the same bread knife and workbenches for products with/without mayonnaise and baked products, and cleaning bread knife and workbenches with the same rag. We identified this Salmonella Enteritidis outbreak as associated with environmental cross-contamination, possibly from mayonnaise. We recommend food handlers to use separate tools and workbenches for baked and unbaked products/ingredients and make mayonnaise with sanitized eggs