E. coli Hangs Out in Buildings

Study finds fairgoers sickened by an infected barn

TUESDAY, Nov. 25, 2003 (HealthDayNews) -- In a twist on the concept of "sick building syndrome," an Ohio county fair barn apparently became infected with an airborne strain of E. coli and sickened dozens of people.

Federal officials, who analyzed the outbreak two years ago in a just-published report, now suspect that fairs could be an even greater hotbed of E. coli germs than experts had previously thought.

"When people go to county fairs, they should be aware of these potential exposures and should take precautions -- in particular, washing their hands before eating," says study co-author Dr. Paul S. Mead, an epidemiologist with the U.S. Centers for Disease Control and Prevention (CDC).

The outbreak of infection with the germ called Escherichia coli O157:H7, which is found in cows, hit people who attended the Lorain County Fair from Aug. 20 to 26, 2001. Federal and local health officials, who analyzed the outbreak, report their findings in the Nov. 26 issue of the Journal of the American Medical Association.

The researchers studied 23 infected people -- many of them teenagers -- and 53 other people who attended the fair but did not get sick. Six of those infected were hospitalized, and two developed a serious kidney condition.

Researchers also examined a multipurpose building at the Ohio county fair and found E. coli germs all over the place, from the rafters to the sawdust on the floor to other surfaces. Tests matched the germs to those found in the infected patients. The room had been used for dances and other events.

Apparently, the germs found their way into the sawdust and then got stirred up, Mead says, adding, "Anybody who's been to a barn dance knows it can be fairly dusty."

Once the germs were in the air, they may have easily found their way into the intestines of the infected people. "This bacterium can go from the environment to a person's hands to their food," says Mead.

People who visited the building to show their farm animals were less likely to have come down with the E. coli strain, possibly because they had been infected before and developed some kind of immunity, the report says.

"It would not be surprising to see immunity in people who are repeatedly exposed, but we know that immunity is not likely to be complete," Mead says.

Some kinds of E. coli germs are ordinary, harmless inhabitants of the human digestive system. They normally don't cause any problems unless they somehow escape the intestines and get into the body.

But other kinds of E. coli, like the O157 strain, spell trouble if they land in the intestines of humans. Infection can happen when people eat contaminated food or water -- vegetables with bits of fertilizer left on them, for instance -- or when they eat after touching cows or manure. People can also get infected if they come in contact with the stool of infected people.

E. coli O157 poisons the small intestine and prevents it from removing fluid from the stool, leading to diarrhea, says Dr. Roger Bitar, chief of the infectious disease division at the Kaiser Permanente Health Plan in San Diego.

An estimated 70,000 Americans are sickened each year by the O157 strain, and 60 die. Most famously, in 1993, four children died in the Northwest after eating fast-food hamburgers.

What to do? Both Mead and Bitar say the risk of airborne E. coli is yet another reason to emphasize hand-washing. If germs aren't on your hands, you'll be less likely to get infected -- and still be able to do-si-do at the local barn dance.

More information

Get details about E. coli O157 and farm animals from the CDC. For more on E.coli O157 and water contamination, visit the Environmental Protection Agency.

SOURCES: Paul S. Mead, M.D., M.P.H., epidemiologist, U.S. Centers for Disease Control and Prevention, Ft. Collins, Colo.; Roger Bitar, M.D., M.P.H., chief, infectious disease division, Kaiser Permanente Health Plan, San Diego; Nov. 26, 2003, Journal of the American Medical Association
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