Very high rates of HIV infection among gay/bisexual male youths in the United States

Over a quarter of new HIV infections in the US involve young people aged between 13 and 24, investigators report in the November 27th edition of MMWR Weekly Report. Approximately 75% of these infections involved gay and bisexual young men. The study also found that HIV testing rates in this age group were low.

“More effort is needed to provide effective school- and community-based interventions to ensure all youths, particularly MSM [men who have sex with men] have the knowledge, skills and resources necessary to avoid HIV infection,” write the authors. “Health-care providers and public health agencies should ensure that youths are tested for HIV and have access to sexual health services, and that HIV-positive youths receive ongoing health-care and prevention services.”

In 2009, young people represented 7% of people living with HIV in United States. The majority (60%) of young people living with HIV were unaware of their infection, indeed the prevalence of undiagnosed HIV is higher among 13 to 24 year olds than any other age group.

Investigators wanted to estimate the overall prevalence of HIV among young people; the incidence of new infections in 2010; rates of HIV testing; and the percentage of young people who engaged in HIV risk behaviours.

The study was based on data obtained from a number of sources, including the National HIV Surveillance System; the Youth Risk Behavior Surveillance System; and the National Youth Risk Behavior Survey. This information was combined with data collected from twelve US states regarding the risk behaviour of high school students.

At the end of 2009, the prevalence of diagnosed HIV among young people was 70 per 100,000. However, rates differed significantly between states, from a low of 2 per 100,000 to a high of 563 per 100,000. Rates were higher in the South and Northeast compared with the West and Midwest.

There were an estimated 47,500 new HIV infections in the US in 2010, and 12,200 (26%) were in young people. Most of the infections in this 13 to 24 age group involved young men (83%).

Rates of new HIV infections among young people differed according to race/ethnicity and were highest among African Americans (57%), followed by Hispanic/Latino (20%) and white people (20%).

Almost three-quarters (72%) of new infections in 13 to 24 year olds were attributed to sex between men. A further 5% of infections were due to a combination of sex between men and injecting drug use.

Restricting analysis to men showed that 87% of new infections were in gay/bisexual men.

The majority (54%) of new infections in gay/bisexual men involved African Americans.

The investigators then looked at HIV risk behaviours among high school students. Among those reporting sexual contact, gay and bisexual men were more likely to report four or more partners (39 vs 26%) and injecting drug use (20 vs 3%).

However, this group was less likely to report ever having been taught about HIV at school (75 vs 86%).

Looking at young people who reported that they were currently sexually active, the researchers found that gay/bisexual men were more likely than other groups to report having sex after drug or alcohol use (39 vs 24%) and were significantly less likely to use condoms (44 vs 70%).

HIV testing guidelines in the United States recommend routine tests for everybody aged between 13 and 64 years. The researchers found that 13% of high school students had tested for HIV and only 22% of sexually active young people had tested. Testing rates were higher in women compared to men (27 vs 18%) and African Americans compared to other ethnic groups (32 vs 20% for Hispanic/Latino and white people).

The overall prevalence of testing among 18 to 24 year olds was 35%. Rates were again higher in women compared to men (45 vs 24%) and African Americans compared to Hispanic/Latino and white people (53 vs 36 vs 30%).

“Public health agencies, in conjunction with families, educators, and health-care practitioners, must educate youths about HIV before they begin engaging in risk behaviors, especially young gay/bisexual males, particularly blacks/African Americans, who face a disproportionately higher risk,” conclude the authors. “To delay the onset of sexual activity, increase condom use among those who are sexually active, and decrease injecting drug use, multicomponent school- and community-based approaches that provide access to condoms, HIV testing and testament, and behavioral interventions for those at highest risk are needed.”