Multistate outbreak of Salmonella typhimurium infections associated with eating ground beef–United States, 2004

Salmonella infections cause an estimated 1.4 million human illnesses and 400 deaths annually in the United States. Although the incidence of several other foodborne bacterial infections decreased substantially during 1996-2004, the incidence of Salmonella infections declined modestly. In September 2004, the New Mexico Department of Health received reports from the New Mexico Scientific Laboratory Division of eight Salmonella enterica serotype Typhimurium isolates that had indistinguishable pulsed-field gel electrophoresis (PFGE) patterns using XbaI and BlnI restriction enzymes. The patients were from three New Mexico counties and had onsets of illness during August 18-29. A review of PFGE patterns submitted to the National Molecular Subtyping Network for Foodborne Disease Surveillance (PulseNet) database for Salmonella revealed 31 indistinguishable patient isolates of S. Typhimurium from nine states (Colorado, Kansas, Minnesota, New Jersey, New Mexico, New York, Ohio, Tennessee, and Wisconsin) and the District of Columbia, with illness onset occurring during August 11-October 2, 2004. The S. Typhimurium isolates were susceptible to all antimicrobial agents tested. An investigation conducted by state health departments, CDC, and the U.S. Department of Agriculture Food Safety and Inspection Service (FSIS) identified ground beef purchased at a national chain of supermarkets as the source of S. Typhimurium infections. Traceback results indicated product originating from a common supplier; however, evaluators determined that plant practices conformed to FSIS production guidelines, and no product recalls were made. This report describes the investigation and underscores the risk for salmonellosis from contact with contaminated ground beef, despite regulatory directives to reduce Salmonella contamination in beef production. Reduced contamination and consumption of raw or undercooked meat and further education of the food service industry and consumers are critical to reducing foodborne salmonellosis.