CROI 2013: New Data on HIV-Related Disparities in Black Gay and Bi Men
Cyprian Wejnert, PhD, an epidemiologist with the Division of HIV/AIDS Prevention at the Centers for Disease Control and Prevention (CDC), launched the conference session with both good news and bad news from a study using data from the National HIV Behavior Surveillance (NHBS) program.
The NHBS focuses on three populations—men who have sex with men (MSM), injection drug users, and heterosexuals at increased risk for HIV infection—in 20 U.S. cities with high HIV prevalence (that is, the proportion of individuals infected with HIV). Data are gathered on access to and use of HIV prevention services, behavioral risks for HIV infection, HIV testing behaviors, and HIV test results. Surveillance of each population rotates annually.
A comparison of data from the 2008 and 2011 surveillance cycles in MSM revealed a “promising increase in awareness of HIV infection,” Wejnert stated in a March 5 press conference. “We found that the proportion of those testing positive as part of our study who were already aware of their infection increased from 56% in 2008 to 66% in 2011.”
In addition, the proportion of MSM with HIV in the study remained relatively steady between the two surveillance years: 19% tested positive for HIV in 2008 and 18% tested positive in 2011. “This suggests that something other than a change of prevalence might be at play among this population,” said Wejnert. “Either our HIV testing efforts are being successful or efforts to reduce stigma may also be being successful. That certainly is promising and warrants further research.”
Digging into study participant demographics, however, revealed disturbing disparities in both HIV prevalence and status awareness in this study population: “We found that black MSM were most likely to be infected with HIV but least likely to know about their infections.”
In the both years, African-American MSM were roughly twice as likely as white MSM to test positive (29% vs 16% in 2008 and 30% vs 14% in 2011). In 2011, only 54% of HIV-positive black MSM had been tested previously and were aware of their HIV status, compared with 86% of white MSM in the study.
These findings support continued and targeted efforts to make HIV testing accessible and destigmatized for black gay and bisexual men, Wejnert added. “With over half of all new HIV infections transmitted by those who are unaware of their infections, it’s important for us to sustain our testing efforts and to eliminate disparities to dramatically reduce HIV in the United States,” he concluded.
The second presentation in this same conference session explored age and racial/ethnic disparities in per-contact risk of HIV infection among U.S. MSM.
Hyman Scott, MD, of the University of California at San Francisco prefaced his talk with CDC data showing that, in 2010, African-Americans represented 12% of the U.S. population but accounted for 45% of new HIV infections. “In particular,” he added, “young black MSM have seen a 48% increase in HIV incidence between the years of 2006 and 2009.”
“This disparity is not fully explained by individual risk behaviors,” said Scott. “Social and sexual networks are likely important drivers for these disparities among MSM in the U.S., particularly black MSM.”
(Indeed, a recent meta-analysis of 194 studies looking at HIV-related racial disparities among MSM in the U.S., Canada, and the United Kingdom found that black MSM were more likely than other MSM to report any preventive behavior, such condom use, HIV testing, or having fewer sex partners, less drug use before or during sex, or ever using post-exposure or pre-exposure prophylaxis.)
For the part of their study that looked at HIV infection disparities, Scott and colleagues analyzed data from three large cohort studies, conducted between 1995 and 2003 (the early days of highly active antiretroviral therapy, or HAART), with a combined total of 10,760 participants. HIV infections occurred in 584 of these individuals. The analysis focused on reported events, or contacts, of unprotected intercourse with known-HIV-positive partners.
Younger MSM (under age 25) and black MSM had a higher risk of becoming HIV positive. Compared with white MSM, Latino MSM, and MSM of other ethnicities not specified in the report, black MSM reported the fewest sexual contacts (that is, the number of times a specific sex act occurred). In fact, the average number unprotected receptive anal sex contacts reported by white MSM was three times greater than that of black MSM (10.8 vs 3.1).
Looking at per-contact risk of HIV infection (PCR for short), “we found that black MSM and MSM classified as ‘other’ had approximately 50% higher PCR estimates compared to white or Latino MSM for URA [unprotected receptive anal intercourse] with HIV-positive partners,” said Scott, although he noted these differences were not statistically significant. Similar elevations were seen among MSM of color for unprotected insertive anal intercourse with HIV-positive partners, he added, with Latino MSM having a significantly higher risk of acquiring HIV compared with white MSM.
“Despite a lower number of contacts with HIV-positive partners, younger MSM and MSM of color had higher per-contact risk” of acquiring HIV, Scott stated.
Scott acknowledged the study’s limitations; for example, the data used came from studies that ended in 2005 or earlier. Since then, “there have been changes in the epidemiology of the HIV epidemic and [antiretroviral treatment] prescribing practices and guidelines.”
Still, he concluded, the results support the hypothesis that “partner or other susceptibility factors…may explain observed racial/ethnic disparities in HIV incidence.”
Results from the studies presented today by Wejnert and Scott emphasize the urgent need to design, fund, and implement HIV testing and prevention programs for young MSM and black MSM, to alleviate disparities in HIV infection rates. Wejnert shared in the afternoon’s press conference that “one thing we’re finding is that the higher-risk groups also tend to be the hardest to find….That’s definitely a high-priority area, and it’s part of the ‘high-impact prevention’ plan that CDC is implementing.”
Webcasts of Dr. Wejnert’s and Dr. Scott’s presentations, complete with slides, are available on the Retrovirus Conference website.
Reilly O’Neal is a freelance writer and former editor of BETA.
Millett, G. and others. Comparisons of disparities and risks of HIV infection in black and other men who have sex with men in Canada, UK, and USA: a meta-analysis. Lancet 380(9839):341–48. July 28, 2012.
Scott, H. and others. Age and racial disparities in per-contact risk of HIV seroconversion among men who have sex with men: US. 20th Conference on Retroviruses and Opportunistic Infections. Atlanta. March 3–6, 2013. Abstract #91.
Wejnert, C. and others. HIV prevalence and awareness of infection in 2008 and 2011 among men who have sex with men: 20 US cities. 20th Conference on Retroviruses and Opportunistic Infections. Atlanta. March 3–6, 2013. Abstract #90.