Study of 21 cities: 1 in 5 men who have sex with men has HIV

ST LOUIS (MD Consult) – Approximately 1 in 5 (19%) men who have sex with men (MSM) in a study of 21 major US cities is infected with HIV, and nearly half (44%) of those men are unaware of their infection, according to a new analysis
released last week by the Centers for Disease Control and Prevention (CDC). In the study, young MSM and MSM of color were least likely to know their HIV status.

"This study's message is clear: HIV exacts a devastating toll on men who have sex with men in America's major cities, and yet far too many of those who are infected don't know it," said Kevin Fenton, MD, director of CDC's National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention. "We need to increase access to HIV testing so that more MSM know their status, and we all must bring new energy, new approaches, and new champions to the fight against HIV among men who have sex with men."

The study's results bolster key themes in President Obama's National HIV/AIDS Strategy for the United States. The recently released strategy states that "the United States cannot reduce the number of HIV infections nationally without better addressing HIV among gay and bisexual men," and MSM are listed among the priority populations on which to focus HIV prevention efforts. The President's strategy also sets targets for reducing the number of individuals living with HIV who are unaware of their HIV status.

The CDC study tested 8,153 MSM in 21 cities participating in the 2008 National HIV Behavioral Surveillance System (NHBS) and examined HIV prevalence and awareness of HIV status among this group. NHBS monitors HIV testing, risk behaviors, and access to prevention services among at-risk populations in cities with high numbers of persons living with AIDS.

While MSM of all races and ethnicities were severely affected, black MSM were particularly impacted: 28% of black MSM were HIV-infected, compared with 18% of Hispanic and 16% of white MSM.

The study also found a strong link between socioeconomic status and HIV among MSM: prevalence increased as education and income decreased, and awareness of HIV status was higher among MSM with greater education and income. These findings echo similar disparities found in recent NHBS research among heterosexuals.

Low awareness of HIV infection a major concern, particularly for younger men

The study provided additional insight into the populations of MSM most in need of HIV testing and prevention:

• Among racial/ethnic groups, black MSM with HIV were least likely to be aware of their infection (59% unaware, vs. 46% for Hispanic MSM and 26% for white MSM).
  
  
• While young MSM (under age 30) had lower HIV prevalence than older men, they were far more likely to be unaware of their HIV infection. Among MSM aged 18-29 who had HIV, nearly two-thirds (63%) were unaware, versus 37% for men age 30 and older.
  
  
• Among young MSM, young MSM of color were less likely than whites to know they were HIV-infected. Among HIV-infected black MSM under age 30, 71% were unaware of their infection; among HIV-infected Hispanic MSM under age 30, 63% were unaware. This compares with 40% of HIV-infected white MSM under age 30 who were unaware.
  
  

CDC officials note that low awareness of HIV status among young MSM likely reflects several factors: they may have been infected more recently, may underestimate their personal risk, may have had fewer opportunities to get tested, or may believe that advances in HIV treatment minimize the threat of HIV. For young MSM of color, discrimination and socioeconomic factors—such as poverty, homophobia, stigma, and limited health-care access—may be especially acute and pose particular challenges.

"For young men who have sex with men—including young men of color who are least likely to know they may be infected—the future is truly on the line," said Jonathan Mermin, MD, director of CDC's Division of HIV/AIDS Prevention. "It is critical that we reach these young men early in their lives with HIV prevention and testing services and continue to make these vital services available as they become older."

The CDC estimates that the majority of new sexually transmitted infections are transmitted by individuals who are unaware of their infection, and studies show that once people learn they are HIV-infected, most take steps to protect their partners. Therefore, because undiagnosed infection likely plays a major role in HIV transmission, reaching younger MSM with regular HIV testing is critical.

The CDC recommends that MSM of all ages get tested for HIV at least annually, or more often (every 3 to 6 months) if they are at increased risk (eg, those with multiple or anonymous sex partners or who use drugs during sex). Notably, only 45% of HIV-infected MSM who were unaware of their infection had been tested in the past year, underscoring the importance of more frequent testing among those at highest risk.

While HIV prevention for MSM remains a top CDC priority, agency officials note that a renewed national commitment to HIV prevention is needed to reduce the toll of HIV on MSM and increase access to prevention.