Cumulative AIDS incidence and altered mortality from bacterial infections. To determine whether populations with high cumulative incidence of acquired immunodeficiency syndrome (AIDS) experienced increased deaths from sepsis, central nervous system abscess, or endocarditis, New Jersey AIDS patients were grouped according to their age, sex, race, and residence-specific cumulative incidence of AIDS since the onset of the AIDS epidemic. Between 1980 and 1986, among 25-44 year olds in the highest cumulative incidence group for AIDS, sepsis mortality increased from 3.3 to 15.2 deaths/100,000/year, an increase of 11.9 deaths/100,000/year (95% confidence interval (6.9, 17.0) deaths/100,000/year); mortality from central nervous system abscesses increased from zero to 1.7 (0.1, 3.2) deaths/100,000/year; and mortality from endocarditis increased from 0.8 deaths/100,000/year to 2.4 deaths/100,000/year, an increase of 1.6 (-0.5, 3.7) deaths/100,000/year. Age-matched New Jersey patient populations with low cumulative incidence of AIDS did not sustain a similar increase. The HIV disease-associated increase in sepsis mortality among young populations represents a new component of the substantial increase in U.S. sepsis mortality that occurred over the last two decades, but was previously limited to older populations. 