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Escherichia coli O157:H7 Infections Associated with Eating a Nationally Distributed Commercial Brand of Frozen Ground Beef Patties and Burgers -- Colorado, 1997

The Colorado Department of Public Health and Environment (CDPHE) recently identified an outbreak of Escherichia coli O157:H7 infections associated with eating a nationally distributed commercial brand of frozen beef patties and burgers. This report describes the preliminary findings of the ongoing investigation of this outbreak and the product recall of six lots of Hudson Foods frozen ground beef patties and burgers.

On August 7, 1997, CDPHE's state public health laboratory reported that 15 (56%) of 27 E. coli O157:H7 isolates submitted for routine molecular subtyping since June 1 were characterized by highly related pulsed-field gel electrophoresis (PFGE) patterns; the PFGE patterns of 13 (87%) of 15 isolates were indistinguishable (outbreak strain). The patterns of the remaining two isolates were indistinguishable from each other and differed from the outbreak strain by only one band. These isolates were cultured from stool specimens obtained from 15 patients who had onsets of illness during June 14-July 14. The median age of these patients was 13 years (range: 3-76 years); 11 (73%) were male. Five patients were hospitalized, but none developed hemolytic uremic syndrome or died. Eleven (79%) of 14 patients reported eating frozen pre-formed ground beef patties or burgers at least once during the 7-day period preceding illness onset; eight specifically recalled eating Hudson Foods brand product, and three, who could not recall a specific brand name, identified package labeling consistent with Hudson Foods brand. Hudson Foods beef burgers collected from the freezers of two of the 15 patients bore the identical lot number (156A7); both yielded E. coli O157:H7 when cultured at the U.S. Department of Agriculture's (USDA's) Food Safety and Inspection Service Laboratory in Athens, Georgia. The PFGE pattern from one isolate cultured from ground beef was indistinguishable from the outbreak strain; PFGE analysis of the second isolate is pending.

In cooperation with USDA, Hudson Foods recalled from retail stores three potentially contaminated lots of Hudson beef burgers on August 12 (Lots: 156A7, 156B7, and 155B7), and three additional lots on August 15 (Lots: 155A7, 160A7, and 160B7). As of August 20, no additional lots had been recalled. Preliminary findings suggest that these lots could have been distributed to at least all 48 contiguous states. USDA is continuing efforts to assure that all suspect product is recalled and to determine potential contamination points during the manufacturing process. In addition, CDC is working with state health departments to determine whether other cases of E. coli O157:H7 infection are associated with exposure to Hudson Foods products.

Reported by: El Paso County Dept of Health and Environment, Colorado Springs; Larimer County Dept of Health and Environment, Ft. Collins; Mesa County Health Dept, Grand Junction; Pueblo City-County Health Dept, Pueblo; Tri-County District Health Dept, Englewood; P Shillam, MSPH, D Heltzel, J Beebe, PhD, R Hoffman, MD, State Epidemiologist, Colorado Dept of Public Health and Environment. State public health laboratories of Minnesota, Oregon, Texas, Utah, Virginia, and Washington. Food Safety and Inspection Svc, US Dept of Agriculture. Foodborne and Diarrheal Diseases Br, Div of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, CDC.

Editorial Note

Editorial Note: Illness caused by E. coli O157:H7 infection usually is characterized by abdominal cramping, diarrhea, and bloody stools and can be complicated by hemolytic uremic syndrome and death. Persons with illness meeting this description (i.e., abdominal cramping, diarrhea, and bloody stools) should contact their physicians. Additional information about the product recall is available from the USDA Meat and Poultry Hotline, telephone (800) 535-4555.

The investigation of this outbreak illustrates the value of molecular subtyping in enhancing surveillance for E. coli O157:H7 infections. The National Molecular Sub-typing Network for Foodborne Pathogenic Bacteria has enabled CDPHE's laboratory and 14 other state public health laboratories to subtype E. coli O157:H7 isolates. Four of these laboratories, designated as area laboratories, also can subtype isolates from surrounding states. As of August 19, none of 340 E. coli O157:H7 isolates subtyped at six other network laboratories matched the outbreak strain.

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