THE CHANGING AIDS EPIDEMIC IN NEW-YORK-CITY - A DESCRIPTIVE BIRTH COHORT ANALYSIS OF AIDS INCIDENCE AND AGE AT DIAGNOSIS

Objective: To describe and quantify changing AIDS incidence trends in New York City. Methods: Data on 44400 AIDS cases diagnosed and reporte d between 1981 and 1992 were analyzed among demographic and HIV transm ission categories. Data were grouped into 10-year birth cohorts by sex , race/ethnicity, and mode of HIV transmission. AIDS incidence and rat es of change, as well as changes in median age at diagnosis, were anal yzed for persons born between 1920 and 1969. Results: Declining AIDS i ncidence between 1989 and 1992 was only observed among white men who h ave sex with men (MSM) born prior to 1960 and among minority MSM born prior to 1940. Between 1989 and 1992 the highest rate of increase in A IDS incidence was observed among female injecting drug users (IDU) and persons born after 1960. Median age at diagnosis increased during the study period by 1 year among white MSM, by 2 years among minority MSM , by 7 and 6 years among male and female IDU, respectively, and by 5 y ears among women infected through heterosexual contact. Conclusions: T hese findings suggest that early HIV infection dynamics of the AIDS ep idemic were differentially related to age, sex, and transmission categ ory, which resulted in the diffusion of infection from older to younge r cohorts and from men to women. The continuing increase in AIDS incid ence among the 1960s cohort suggests that the future growth of the epi demic will be dependent upon infection patterns of younger birth cohor ts.