Nosocomial outbreak of gastroenteritis due to Salmonella senftenberg

We describe a prolonged nosocomial outbreak of Salmonella senftenberg, an uncommon human pathogen. We detected 22 cases of infection due to S. senftenberg that occurred from March 1993 through November 1994 and involved 18 patients and four healthy employees. All infected persons had consumed food prepared by the hospital kitchen. The estimated attack rate for the period of the outbreak was 0.19-0.23 cases per 100,000 meals served. Infection control interventions included observation of food preparation, disinfection of kitchen devices, and education of food handlers. The consumption of lettuce (11 of 15 patients who could recount extended dietary histories vs. 4 of 20 controls; P = .005), cauliflower (5 of 15 vs. 0/20; P = .02), cottage cheese (4 of 15 vs. 0/20; P = .03), and deli turkey (8 of 15 vs. 0/20; P < .001) was associated with S. senftenberg infection. The isolates had identical antibiograms and pulsed-field gel electrophoretic patterns. Cultures of stool samples from food handlers as well as food items, kitchen devices, and kitchen surroundings were negative for S. senftenberg. Interruption of the outbreak occurred coincidentally with the institution of infection control measures. This prolonged outbreak of salmonellosis was probably related to contamination in the kitchen from turkey, with cross-contamination via equipment.