HIV more prevalent among black MSM despite fewer risk behaviors
ATLANTA Individual behavioral risk factors for HIV do not explain elevated HIV rates among black men who have sex with men, according to data from a recent CDC study.
Emphasis on risk behavior in black MSM may be misguided because risk behavior may have little effect on racial disparity in HIV infection rates, the researchers said.
The study was conducted to identify factors contributing to racial disparity in HIV prevalence between black and white MSM in the United States. The study is the first quantitative meta-analysis to compare risk behaviors among MSM by race since the HIV/AIDS epidemic began.
As many as 46% percent of black MSM have HIV, according to data from another recent CDC study conducted in five U.S. cities. In comparison, the HIV rate is estimated at 21% for white MSM and 17% for Hispanic MSM.
Overall, blacks represent about 13% of the U.S. population, but account for about half of all patients with HIV.
This is 26 years into the epidemic, so we do have some way to go in increasing the penetration of our prevention interventions, said Kevin A. Fenton, MD, PhD, director of the National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention at the CDC, and member of the Infectious Disease News editorial advisory board. Fenton spoke at the 2007 National HIV Prevention Conference.
Researchers said that high rates of unprotected sex in the early years of the epidemic, high STD prevalence and, among HIV-positive black MSM, a lesser uptake of antiretroviral therapy, may have contributed to greater HIV transmission among black MSM.
Our analysis points to the need for further research to examine the degree to which factors such as social networks, along with high rates of HIV prevalence and STDs, contribute to the high HIV rates among black MSM, said Gregorio Millett, MPH, a behavioral scientist at the CDC. We also need to consider factors beyond individual risk behaviors that place some racial and ethnic groups at greater risk for HIV infection compared with others.
Millett, who was one of the researchers on the recent study regarding race and HIV risk factors, presented results at the 2007 National HIV Prevention Conference.
The researchers analyzed 53 quantitative studies of MSM that stratified behaviors and HIV risk by race. The literature search for the MSM and race-specific studies included electronic databases, online bibliographies and publication reference lists.
All studies were published between 1980 and 2006. Meta-analyses were performed to compare HIV risk behaviors between black MSM and white MSM.
Less risk, more effect
Black MSM were 58% less likely to disclose same-sex behavior and were 71% less likely to identify themselves as gay. However, no differences by race were found in MSM who reported unprotected anal intercourse in the past year, six months, three months or last sexual encounter. Black MSM aged 15 to 29 years were 34% less likely to report unprotected anal sex than white MSM in the same age group.
Black MSM were also 36% less likely to report as many lifetime male sex partners than white MSM, 29% less likely than white MSM to report any substance abuse and 36% less likely than white MSM to use drugs associated with HIV infection. Despite reporting fewer risk behaviors, black MSM were twice as likely as white MSM to be diagnosed with a current STD.
Across studies from the 1990s and from 2000 to 2006, the researchers found no differences by race in unprotected anal; but black MSM were 60% more likely than white MSM to report unprotected anal intercourse during the 1980s.
Unprotected anal sex in the first decade of the HIV/AIDS epidemic may have influenced the current epidemic among black MSM, the researchers said. Black MSM tend to have sex with other black MSM, and Millet and colleagues theorize that this intraracial sexual mixing may have established a greater background prevalence in black MSM communities early in the epidemic and given rise to the current racial disparity.
Other factors that the researchers believe help sustain the greater rates of HIV transmission among black MSM include high STD rates and high viral load among HIV-positive black MSM. Black MSM with HIV in the study were 57% less likely to report taking antiretroviral therapy than HIV-positive white MSM.
No differences by race were reported in commercial sex work, sex with a known HIV-positive partner or HIV testing history. – by Kirsten H. Ellis
For more information:
- Millett G, Flores S, Peterson J, Bakeman R. Black-white disparities in HIV infection among men who have sex with men: a meta-analytic examination of HIV risk behaviors. Presented at: The 2007 National HIV Prevention Conference; Dec. 2-5, 2007; Atlanta.
- Millet GA, Flores SA, Peterson JL, Bakeman R. Explaining disparities in HIV infection among black and white men who have sex with men; a meta-analysis of HIV risk behaviors. AIDS 2007; 15:2083-2091.