Washington, D.C. -- Results of the first survey focusing solely on "men who have sex with men" in four major U.S. cities show new estimates of HIV prevalence rates, report University of California San Francisco researchers.
The overall prevalence of HIV infection has declined significantly from estimates in the mid-1980s, but some segments of the study population--known by the abbreviation MSM--continue to have very high levels. The decline is attributed to the high death rates from HIV-related disease from 1982-95 and the success of prevention efforts in keeping the incidence of new HIV infection at low levels, according to the UCSF research team.
Findings from the "UCSF Urban Men's Health Study" were reported here today (November 18) at the meeting of the American Public Health Association. Unlike other studies focusing on the incidence of HIV among gay men, this project targeted MSMs both inside and outside of traditional gay neighborhoods, including men who identified themselves as heterosexual or bisexual.
The research includes data from 2,800 men in four urban areas--San Francisco, Los Angeles, New York, and Chicago. Participants in the study answered questions covering a wide range of topics on HIV and health issues during a 90-minute phone interview during 1997-98.
Joseph Catania, PhD, UCSF associate professor of medicine, was study principal investigator, and Ron Stall, PhD, MPH, UCSF assistant professor of epidemiology, was co-principal investigator. They are affiliated with the UCSF Center for AIDS Prevention Studies and the UCSF AIDS Research Institute.
"Assuming that HIV infection rates in the mid-80s were similar across these cities, we conclude that HIV prevalence rates have declined 60-70 percent from the tragic levels then to the present numbers, which unfortunately are still unacceptable," said Catania.
"Among MSMs, the high risk groups include men who are of low socio-economic status, African-American, intravenous drug users, and heavy users of illegal substances. It is a tragic fact that the HIV rates in these population segments are among the highest in the world," he added.
The majority of participants in the study identified themselves as being gay. About seven percent reported being either heterosexual or undecided about their sexual orientation, with more than 90 percent in this group reporting an experience of same-gender sex during adulthood.
About 20 percent of participants were men of color, and six percent were elderly.
"Our findings show that the majority of HIV-positive men are accessing HIV therapy, but not all men are accessing care at a level appropriate to their HIV disease," Stall said. "We found lower socio-economic status, less social support, and greater recreational substance abuse to be strongly associated with those who did not access appropriate care, so this information is important for health outreach programs directed at the MSM community."
The UCSF team presented the study results at a special symposium at the APHA meeting. Catania reported on HIV prevalence rates, while Stall presented findings on access to treatment and use of therapies. Thomas C. Mills, MD, MPH, UCSF associate professor of psychiatry, reported on HIV and the "gay ghetto," and Jay Paul, PhD, UCSF specialist in epidemiology, reported on childhood sexual abuse and sexual risk-taking behavior.
Study findings in these four areas include:
HIV prevalence rates
• The HIV-positive rate for MSMs in all four cities was 17 percent. Specific rates for MSMs were 20 percent for San Francisco and Los Angeles and 14 percent for New York and Chicago.
• The HIV-positive rates within different population segments of MSMs were diverse, with wide variation in categories defined by socio-economic status, race, intravenous drug use, and substance abuse.
• The HIV rate was 10 percent for MSMs of higher socio-economic status and 33 percent for those of lower status.
• In racial/ethnic groups, the HIV rates were African American, 29 percent; Hispanic, 18 percent; Native American, 24 percent; white, 16 percent; and Asian/Pacific Islander, 9 percent.
• The rate of HIV among MSMs who were injection drug users was 44 percent, while the rate for MSM non-users was 15 percent.
• The HIV rate among MSMs who were illegal substance users (but not injection drug users) was 21 percent for weekend users and 33 percent for users five days or more per week. This compares to an HIV rate of 12 percent in MSMs who were non-users.
Access to treatment and use of therapies
• More than 80 percent of MSMs were using antiretroviral drugs at recommended levels of CD-4 cell counts (below 500). CD-4 cells, also called T-helper cells, coordinate the overall action of the immune system, and they are a primary target of HIV infection.
• More than 90 percent of the HIV-positive men in the study were undergoing antibiotic prophylaxis treatment to prevent the onset of pneumonia at recommended levels of CD-4 cell counts (below 200).
• Characteristics of HIV-positive MSMs who were following recommended therapies were: older age group (40-49 vs. 18-39 years), white, college graduate, higher income, and a sense of connection to the gay community.
• Men who were heavy alcohol users were less likely to be following recommended therapies.
HIV and "gay ghettos"
• MSMs living outside a city's gay neighborhoods were less involved in the gay community and more likely to self-identify as heterosexual or bi-sexual.
• MSMs outside the gay ghettos were more likely to be HIV negative.
Sexual abuse
• Nineteen percent of study participants reported experiencing childhood sexual abuse by either gender prior to the age of 17.
• Those who reported sexual abuse were more likely than other population groups to report sex forced with a threat of violence or with the use of a weapon (42 percent of those abused).
• Those who reported an experience of childhood sexual abuse were more likely to have engaged in unprotected anal intercourse in the year previous to the study interview (37 percent) and more likely to be HIV-infected (23 percent).
The UCSF study team also included co-investigators Dennis Osmond, PhD; Diane Binson, PhD; Lance Pollack, PhD; Jesse Canchola, MS; Kyung-Hee Choi, PhD; Thomas Coates, PhD; Lawrence Fisher, PhD; Charles Turner, PhD; and Steve Morin, PhD. The research was supported by grants from the National Institute of Mental Health.