The geographic and ethnic diversity of AIDS incidence trends in homosexual/bisexual men in the United States.

We examined geographic and racial/ethnic variation in acquired immune deficiency syndrome (AIDS) incidence in homosexual and bisexual men (i.e., men who report sex with men: MSWM) not using i.v. drugs in the United States. The AIDS incidence in these men has continued to increase in the United States. Incidence increased much less rapidly after 1986 in the three metropolitan statistical areas (MSAs) with the most cases, New York City, Los Angeles, and San Francisco, and may have reached a plateau in these areas. This change in incidence occurred in non-Hispanic black and Hispanic MSWM as well as in non-Hispanic whites in these MSAs, but earlier in whites. There have been similar changes in incidence (but later in time) in all other MSAs with a population of at least 1,000,000 combined, with more tendency toward a plateau in whites than in non-whites. In contrast, incidence increased linearly through 1989 in MSAs with a population less than 1,000,000 and in rural areas, with no change in trend after 1986. Changes in human immunodeficiency virus (HIV) infection incidence before 1985, better therapy and medical care, and migration all contributed to these changes in incidence, as may have changes in reporting. Continued HIV seroconversions among MSWM show that efforts to prevent HIV infection must be continued in all areas of the United States.