Jun 25, 2008 (CIDRAP News) – Federal and state officials yesterday reported an Escherichia coli O157:H7 outbreak that has sickened at least 24 patients in Michigan and Ohio, and state officials say their investigations are pointing to ground beef as the likely source.
So far, 24 cases have been linked though epidemiologic studies and genetic fingerprinting to the outbreak, the US Centers for Disease Control and Prevention (CDC) said in a statement yesterday. Eleven of the patients are from Michigan, and 13 are Ohio residents.
The CDC said illness onset dates for the patients were between late May and early June. Fourteen patients were hospitalized, and one patient developed hemolytic uremic syndrome (HUS), a potentially deadly kidney condition. No deaths were reported.
While urging consumers to take precautions to avoid E coli exposure from ground beef and other possible sources, the agency did not specify a suspected source of the infections. However, Ohio officials today confirmed that E coli O157:H7 found in a raw ground beef sample provided by one case-patient matched the outbreak strain, according to a joint press release from the state's agriculture and health departments.
The contaminated beef was purchased at a Kroger Marketplace in Gahanna, Ohio, but officials said beef purchased from other sources may also be tainted and that consumers should observe ground beef precautions. A second sample bought by a consumer from a Kroger store in Fairfield County tested negative for the pathogen, but authorities did not say if the consumer was involved in the outbreak.
Robert Boggs, director of the Ohio Department of Agriculture, said in the press release that the department was working with the US Department of Agriculture on a trace-back investigation.
Ohio officials also said today that 17 state residents have been sickened in the outbreak so far, four more than the CDC's total from yesterday, and that there were two more probable cases.
In related developments, Michigan's Department of Community Health (MDCH) yesterday issued a public health alert because more than half of its case-patients reported purchasing and consuming ground beef from Kroger stores. A product trace-back investigation is underway, and other retailers and outlets might be identified, the department said.
MDCH officials also said they have confirmed 15 E coli cases that are linked to the outbreak, four more than the CDC's total yesterday.
Don Koivisto, director of the Michigan Department of Agriculture, said in the statement that Kroger is fully cooperating with state and federal investigators.
E coli O157:H7 outbreaks are most often associated with ground beef, though some outbreaks in recent years have involved fresh produce. The strain produces a toxin that causes diarrhea—often bloody—and abdominal cramps but typically no fever. The illness usually resolves in 5 to 10 days, but it can cause HUS in 2% to 7% of patients.
Jun 24 CDC press release
Jun 25 press release from Ohio agriculture and health departments
Jun 24 MDCH public health advisory