Salmonella serotype Typhimurium outbreak associated with commercially processed egg salad--Oregon, 2003

On September 24, 2003, Oregon epidemiologists noted an increase in Salmonella enterica serotype Typhimurium isolates tested during September at the Oregon State Public Health Laboratories. Of 16 isolates, six had matching pulsed-field gel electrophoresis (PFGE) patterns. The laboratory findings prompted an investigation by Oregon Health Services and CDC that identified 18 cases of infection with S. Typhimurium linked to kits for making egg salad that were distributed by a vendor to a supermarket chain. The Food and Drug Administration (FDA) conducted an environmental investigation but was unable to determine the mechanism of contamination. This was the first reported S. Typhimurium outbreak associated with a commercially processed, widely distributed, hard-boiled egg product. Epidemiologists and other public health staff should continue to investigate apparent clusters of salmonellosis and be aware that even commercially processed egg products can be a source of Salmonella.