Multistate outbreak of Salmonella serotype Typhimurium infections associated with consumption of restaurant tomatoes, USA, 2006: Hypothesis generation through case exposures in multiple restaurant clusters

Abstract

Multiple salmonellosis outbreaks have been linked to contaminated tomatoes. We investigated a multistate outbreak of Salmonella Typhimurium infections among 190 cases. For hypothesis generation, review of patients' food histories from four restaurant-associated clusters in four states revealed that large tomatoes were the only common food consumed by patients. Two case-control studies were conducted to identify food exposures associated with infections. In a study conducted in nine states illness was significantly associated with eating raw, large, round tomatoes in a restaurant [matched odds ratio (mOR) 31, 95% confidence interval (CI) 13-73]. In a Minnesota study, illness was associated with tomatoes eaten at a restaurant (OR 63, mid-P 95% CI 105-504, P=0046). State, local and federal regulatory officials traced the source of tomatoes to Ohio tomato fields, a growing area not previously identified in past tomato-associated outbreaks. Because tomatoes are commonly eaten raw, prevention of tomato contamination should include interventions on the farm, during packing, and at restaurants. © Copyright Cambridge University Press 2012.