Venison can contain E. coli bacteria.

A study in Connecticut finds that deer can harbor Escherichia coli O157:H7, the strain of bacterium that causes severe diarrhea in people. The report bolsters a 1997 study by scientists in Oregon who traced E. coli to elk and deer meat. The findings suggest E. coli may be widespread in venison and raise concerns about preparation of wild-game meats.

Microbiologist Douglas W. Dingman and his colleagues at the Connecticut Agricultural Experiment Station in New Haven learned of a case of E. coli poisoning in November 1998, during deer-hunting season. A 7-year-old Connecticut boy had become sick after eating undercooked venison.

The deer had been shot through the abdomen in Vermont but evaded capture for 2 hours, allowing E. coil to escape the gut and invade the bloodstream, Dingman says. The carcass wasn't refrigerated or butchered for 2 days, during which time the outside temperature rose to 55 [degrees] F, ample warmth for bacteria to survive, says Dingman. "This was a classic case of what not to do with deer," he says.

When natural forage gets scarce in November, deer sometimes look for sustenance on farms. The Vermont deer could have eaten food contaminated with the feces of a cow infected with E. coli O157:H7, Dingman says. Cows typically acquire the bacteria from contaminated water.

Tests showed a match between E. coli in the deer meat and that found in the boy, who recovered after antibiotic treatment.

Deer meat can also become tainted when processors mix it with other meats. Idaho state epidemiologist Christine G. Hahn, based in Boise, says that sausage made from combinations of deer, elk, beef, and pork meat--then cured and dried into jerky--contained E. coli O157:H7 that caused an outbreak of illness in the state in 1999.

Because the product wasn't for resale--only for private consumption by the hunters and their families--the processing was not regulated by the U.S. Department of Agriculture, she says. The jerky was subsequently recalled. While it's unclear which of the meats contained the E. coli, Hahn suspects it was the beef.

"This brings into question the whole processing issue," Hahn says. "Most people we talked to ate this [jerky] raw. It looked dried, but it hadn't been cooked all the way."

"I suspect that wild deer and elk may carry E. coli [O157:H7]--that it may be normal flora for them," says clinical epidemiologist William E. Keene of the Oregon Health Division in Portland. Keene, who was an author of the original E. coli venison study in 1997, notes that drying infected meat at 165 [degrees] F for up to 10 hours doesn't always kill the microbes. "Some strains may be more heat-resistant than others," he says.