BACKGROUND: Kansas implemented centralized interviewing for 96 local jurisdictions utilizing OutbreakNet Enhanced (OBNE) funding in January 2016. On September 30, 2016 an increase in Salmonella Newport cases reporting exposure to the Kansas State Fair was detected. Case interviews implicated a food vendor at the fair as the likely source. The local health department (LHD) and Kansas Department of Agriculture (KDA) were notified, and an outbreak investigation was initiated.
METHODS: Persons with laboratory-confirmed Salmonella infection were interviewed with a standard hypothesis-generating questionnaire (HGQ). Stool specimens from ill persons were stereotyped, and pulsed-field gel electrophoresis (PFGE) was performed. A case-control study was conducted to determine if any food items were associated with illness. The implicated food vendor, owned by a non-profit organization, was contacted for a list of their membership for case finding and to obtain controls for the study. A case was defined as illness consistent with salmonellosis in a person that reported eating food from the vendor. Confirmed cases had Salmonella Newport isolates with indistinguishable PFGE patterns, and probable cases were symptomatic or had laboratory evidence of salmonellosis without PFGE. Controls were persons who reported eating food from the vendor who were not symptomatic. Five controls were randomly selected per case. Inspection of the vendor and traceback identification of ingredients were conducted by KDA.
RESULTS: Ninety-five individuals were interviewed; 7 were confirmed and 3 were probable cases. Ten cases and 50 controls were used in the analysis. Both bean burritos (OR=5, 95%CI=0.91–26.85, p=0.05) and pork burritos (OR=7.4, 95%CI=1.65–33.12, p=0.01) were statistically associated with illness. Lettuce, tomatoes, and tortillas were common ingredients in both burritos. KDA’s routine inspection revealed three violations that were corrected during inspection; ingredient traceback has been completed.
CONCLUSIONS: State fairs can foster environments where foodborne and zoonotic disease transmission can occur. This outbreak of Salmonella Newport was associated with eating two different types of burritos from a food vendor at the state fair. Centralized interviews were completed for the first 4 Salmonella cases within at least 3 weekdays of report. This led to the identification of the Salmonella Newport outbreak, 5 days before PFGE results were available to link the cases. Implementation of centralized interviewing has improved the quality and timeliness of Salmonella investigations resulting in the rapid detection of outbreaks leading to a faster more efficient outbreak response.