Science File / An exploration of issues and trends affecting science, medicine and the environment : Bar Patron Tied to One-Third of New Minneapolis TB Cases

“Cheers” it’s not.

A homeless man with grave tuberculosis who hung out at a bar in Minneapolis was responsible for a third of the city’s newly documented TB cases in 1992, researchers say in the New England Journal of Medicine.

Once physicians at the Hennepin County Medical Center diagnosed the 48-year-old man’s TB, they tested 97 people who had come into contact with him, including the bartenders. The man infected 42 of the contacts examined, or nearly half. Of those infected, 14 developed active disease.

Usually, only 1% or 2% of TB infections result in active disease. The researchers do not know whether the man’s TB strain was extra virulent or the patrons’ high rate of alcoholism made them especially susceptible.

Noting that most TB outbreaks occur in residential facilities such as prisons and nursing homes--where prolonged contact with an infected person is more likely--or among people with AIDS, the researchers concluded: “The spread of tuberculosis in a neighborhood bar can be a major public health problem.”