A POPULATION-BASED STUDY DETERMINING THE INCIDENCE OF TUBERCULOSIS ATTRIBUTABLE TO HIV-INFECTION

Although the tuberculosis (TB) epidemic has been attributed in part to the AIDS epidemic, few studies in the United States have measured the risk attributable to HIV infection. We linked the TB registry of Alam eda County, California, 1985 to 1994, with the AIDS registry, 1982 to 1994. We defined a person with TB and HIV infection as a patient in th e TB registry with the same name, race/ethnicity, gender, and date of birth as a patient in the AIDS registry. We used population and HIV se roprevalence estimates to determine the HIV-seropositive and -seronega tive population at risk of TB in 1994. Of 1990 TB cases reported by Al ameda County from 1985 to 1994, 116 (5.8%) had an AIDS diagnosis. Amon g 25- to 44-year-old TB patients, 25.2% of U.S.-born men and 8.4% of U .S.-born women had an AIDS diagnosis. In 1994, the estimated TB incide nce rate in persons with HN infection was 198.1 per 100,000 versus a r ate of 13.9 of 100,000 among persons without HIV infection (rate ratio , 13.8; 95% confidence interval, 8.0, 23.8). In 1994, 93% of TB cases among HIV seropositive persons, 6.4% of all TB cases, and 16.7% of TB cases aged 25 to 44 years were attributable to HIV infection. The high attributable risk underscores the impact of HIV on the TB epidemic. A ll persons with HIV infection should be screened for TB, and persons w ith TB infection should be screened for HIV infection. TB/HIV coinfect ed patients should be provided with TB preventive therapy.