Characteristics of individuals infected during tuberculosis outbreaks may be:
1. U.S. birth. While foreign-born U.S. residents have a rate of tuberculosis 10 times that of native-born residents, the outbreaks were home grown. Thus, U.S.-born residents are more likely to infect others. A total of 91 percent of patients in the 2 tuberculosis outbreaks were born in the United States.
2. African-American race. Most patients in these outbreaks, 67 percent, were non-Hispanic blacks.
3. Alcohol abuse. Alcohol has been previously documented as a risk for tuberculosis infection, and alcohol abuse was found in 51 percent of the patients in the CDC study.
4. Living conditions. Thirty-two percent of patients had a history of incarceration, and 20 percent were homeless.
5. HIV infection. At least 12 percent were infected with HIV. Mitruka noted that this is a mimimum estimate because complete testing data were not available.
6. Other. Substance abuse other than alcohol, and immunosuppression other than HIV were minor factors.