In the United States, the HIV epidemic has had a disproportionate impact on men who have sex with men (MSM), especially young MSM.  Young MSM have had higher rates of new HIV infections than older MSM,^1,2 and recently released HIV surveillance data suggest that the number of new HIV infections may be increasing among the youngest MSM.  Between 2001 and 2006, the number of new HIV diagnoses among MSM 13-24 years old rose dramatically, whereas the number of new diagnoses among MSM in older age groups did not change appreciably.³  To explore behaviors that may place young MSM at greater risk for HIV infection, this fact sheet describes findings from the first MSM cycle of  the National HIV Behavioral Surveillance (NHBS) System.

National HIV Behavioral Surveillance (NHBS) System

NHBS is a cross-sectional survey that collects behavioral information from populations at high risk for HIV infection (MSM, injection drug users, and at-risk heterosexuals).  Each year a different high-risk population is surveyed in a cycle of NHBS.  The first MSM cycle of NHBS (NHBS-MSM1) was conducted from November 2003 to April 2005.  Participants in NHBS-MSM1 were recruited from locations frequented by MSM using time-space sampling.⁴  This fact sheet examines NHBS-MSM1 data from 15 major cities representing all four regions of the country and the U.S. Territories:  Northeast (Boston, MA; New York, NY; Newark, NJ; Philadelphia, PA), South (Atlanta, GA; Baltimore, MD; Fort Lauderdale, FL; Houston, TX; Miami, FL), Midwest (Chicago, IL), West (Denver, CO; Los Angeles, CA; San Diego, CA; San Francisco, CA), and U.S. Territories (San Juan, PR).  The data are from 2,186 men who were 18-24 years old at the time of their NHBS interview and who reported having oral or anal sex with another man in the past year.  These men will be referred to as “young MSM."

Demographic Characteristics

The vast majority of the young MSM interviewed in NHBS were men of color (69%, Table 1).  Nearly all (97%) of the young men self-identified as gay or bisexual.  Although young men from all four regions of the country and the U.S. Territory of Puerto Rico were interviewed in NHBS, larger numbers of men were interviewed in the Northeast, the South, and the West, the three regions with the greatest number of participating cities.

Table 1. Demographic characteristics of the young MSM interviewed.*

Sexual Behavior

Most (89%) of the young MSM interviewed in NHBS reported anal intercourse with a male partner in the past year and nearly half (46%) had anal intercourse without using a condom (unprotected anal intercourse [UAI]), including 17% who had UAI with more than one male partner (Figure 1).  Compared to young men who had UAI with only one male partner, those who had UAI with multiple male partners were more likely to have engaged in UAI with a casual male partner* (77% versus 16%).^†

Figure 1. Number of men with whom the young MSM interviewed^* had unprotected anal intercourse in the past year.

Drug Use

In the year before their NHBS interview, almost half (46%) of the young MSM used drugs that were not prescribed for them.  The most commonly used drug was marijuana (38%), followed by cocaine (16%), ecstasy (15%), amphetamines, including methamphetamine (11%), and nitrite inhalants (“poppers,” 7%).  Moreover, 31% of all the young men reported drug use during sex.  Patterns of drug use during sex were similar to overall drug use patterns; 22% used marijuana during sex, 8% ecstasy, 7% cocaine, 6% amphetamines, and 5% “poppers.” Compared to young men who did not use drugs during sex, those who did were more likely to engage in UAI with a male partner in the past year (52% versus 42%)^† and were more likely to engage in UAI with multiple male partners (25% versus 13%).^†  Rates of UAI were highest among amphetamine users; 73% of young men who used amphetamines during sex reported UAI with a male partner and 47% reported UAI with multiple male partners.

Very few (3%) of the young MSM had ever injected drugs and even fewer (2%) had injected drugs in the past year.  Among those who had injected in the past year, the most frequently injected drugs were amphetamines, cocaine, and heroin.  Injection risk behaviors were relatively modest in these men; in the past year, 26% had injected with a needle that had been used before and 37% had shared injection equipment.

HIV Testing

Of the young MSM interviewed in NHBS, 86% had previously tested for HIV. CDC guidelines recommend that sexually active MSM test for HIV at least annually and that men at higher risk for HIV infection, such as those with multiple male sex partners, methamphetamine users, and those who use drugs during sex, should test at least once every 6 months.⁵  Those young men who did not report any of these high-risk behaviors were more likely to have tested for HIV in accordance with CDC’s guidelines than were those who reported one or more of the high-risk behaviors.  While 69% of the lower-risk, young men met CDC guidelines by testing within the past year, just 58% of the higher-risk, young men met the guidelines by testing within the past 6 months (Figure 2).^†   However, the young men who did not report a high-risk behavior were less likely to have ever tested for HIV; 20% of the lower-risk, young men had never tested compared to just 13% of the higher-risk ones.^†

Figure 2. Time since the young MSM interviewed* had their last HIV test, comparing lower-risk and higher-risk, young men.^†

Prevention Recommendations

Many of the young MSM interviewed in NHBS engaged in UAI in the past year, with a considerable proportion having had UAI with multiple male partners.  Drug use was also common among the men interviewed, and those who used drugs during sex were more likely to engage in UAI.  To reduce the level of high-risk behavior among young MSM, HIV prevention services for these men should be expanded.  CDC endorses a variety of effective HIV prevention interventions for MSM (Diffusion of Effective Behavioral Interventions (DEBI)), including MPowerment for young MSM and Many Men, Many Voices for MSM of color.  Because of the strong association between drug use and UAI, HIV prevention interventions for young MSM should also address substance abuse and provide any needed substance abuse treatment or treatment referrals.  HIV testing services and the promotion of regular testing should be an integral component of interventions as well.  Nearly one in seven of the young men interviewed had never tested for HIV and more than one in four had not tested according to CDC guidelines.  All sexually active young MSM should test for HIV on a regular basis– annually for lower-risk MSM and at least every 6 months for higher-risk MSM.  The need for more frequent testing for higher-risk MSM is particularly important to emphasize since most of the young men interviewed in NHBS reported high-risk behavior.

In summary, this fact sheet describes some of the risk behaviors that contribute to the high rate of HIV infection in young MSM.  To address these risks and thereby lower the rate of infection, prevention services for young MSM need to be comprehensive and employ a variety of interventions, such as behavioral risk reduction, substance abuse treatment, STD screening, and HIV testing, among others.

Additional Information

To learn more about the first MSM cycle of NHBS:

CDC. Human immunodeficiency virus (HIV) risk, prevention, and testing behaviors– United States, National HIV Behavioral Surveillance System: men who have sex with men, November 2003-April 2005 [correction published in MMWR 2006;55(27):752]. MMWR 2006;55(No. SS-6).

For CDC HIV/AIDS information:

http://www.cdc.gov/hiv

For information about HIV testing and the locations of testing sites:

National HIV and STD Testing Resources
1-800-232-4636

For CDC HIV/AIDS resources, technical assistance, and publications:

National Prevention Information Network
1-800-458-5231

The findings and conclusions in this report are those of the author and do not necessarily represent the views of the Centers for Disease Control and Prevention.

References

1. Hoover DR, Munoz A, Carey V, et al. Estimating the 1978-1990 and future spread of human immunodeficiency virus type 1 in subgroups of homosexual men. Am J Epidemiol 1991;134:1190-205.
2. Rosenberg PS, Biggar RJ. Trends in HIV incidence among young adults in the United States. JAMA 1998;279:1894-9.
3. CDC. Trends in HIV/AIDS diagnoses among men who have sex with men– 33 states, 2001-2006. MMWR 2008;57:681-86.
4. MacKellar DA, Gallagher KM, Finlayson T, et al. Surveillance of HIV risk and prevention behaviors of men who have sex with men– a national application of venue-based, time-space sampling. Public Health Rep 2007;122(Suppl 1):39-47.
5. CDC. Sexually transmitted diseases treatment guidelines, 2006. MMWR 2006;55(No. RR-11):9-10.