Demographic, behavioural, economic and biological factors are all associated with increased HIV risk for black men who have sex with men (MSM) in the United States, according to the results of a study published in PLOS ONE. The research involved 1553 black men recruited in six US cities. Men recently diagnosed with HIV were more likely than their HIV-negative peers to be unemployed, to have sexually transmitted infections (STIs) and to report unprotected receptive anal sex. Although not associated with increased HIV risk, the results also showed that many men had symptoms of depression and feelings of internalised homophobia.
“This study enhances Black MSM’s disproportionate risk of HIV, by finding that those who were unemployed and those with untreated STIs were more likely to have undiagnosed HIV infection, raising the possibility that economically-related non-engagement with the health care system may enhance the impact of biological amplifiers of HIV transmission,” comment the authors.
Black MSM have a higher HIV prevalence and incidence than any other sub-population in the US. Previous research has shown that factors including drug use during sex, partner mixing, STIs, poverty and homelessness each contribute to the high rates of HIV seen in black MSM.
A team of investigators wanted to see how these different factors interacted, and designed a study comparing their prevalence among men newly diagnosed with HIV, to the prevalence seen in men with existing HIV infection and in HIV-negative men.
Recruitment to the study (HPTN 061, the "Brothers" study) took place between July 2009 and October 2010. Self-identifying adult black men who had had unprotected anal sex with at least one man in the previous six months were eligible for participation. Recruitment was directly from the community or via sexual networks.
Participants were screened for HIV and STIs on entry to the study. Data were gathered on age, employment status and income. Participants were also interviewed about their sexual behaviour and drug use. Validated scales were used to assess symptoms of depression and internalised feelings of homophobia.
The men had a median age of 40 years; 30% identified as exclusively gay or homosexual, 29% as bisexual and 3% as transgender.
A total of 262 men (16%) had a previous HIV diagnosis and 96 men (8%) were newly diagnosed with HIV.
Over half the men (55%) had not had a college education, 69% were unemployed and 38% had an income of less than $10,000 a year. Only 11% reported a regular partner.
Compared to men who were HIV negative, men who were newly diagnosed with HIV were less likely to be in employment (21 vs 35%, p = 0.01) and less likely to have a college education (35 vs 46%, p = 0.04).
Participants reported a median of five sexual partners in the past six months, and 82% reported two or more male partners. Approximately half (51%) reported unprotected receptive anal intercourse and 75% said they had had unprotected insertive anal sex with a man. Overall, 44% of participants reported sex with a female partner and 25% with a transgender partner. Approximately a third reported transactional sex.
Men who were newly diagnosed with HIV were more likely to report sex with partners of unknown HIV status than men who were previously diagnosed (p = 0.0004) or HIV negative (p < 0.001).
The newly diagnosed men were more likely than their HIV-negative peers to identify as gay or homosexual (42 vs 26%, p =0.004), more likely to report unprotected receptive anal intercourse (69 vs 47%, p < 0.001) and less likely to report sex with a female partner (32 vs 49%, p = 0.002).
Comparison with HIV-negative men also showed that individuals newly diagnosed with HIV were more likely to have rectal gonorrhoea (5 vs 3%, p < 0.001), rectal chlamydia (15 vs 6%, p < 0.001) and at least one STI (31 vs 14%, p < 0.001). Prevalence of STIs was also higher among newly diagnosed men compared to men with previous HIV infection.
Approximately a third (36%) of participants reported using stimulant drugs and 56% reported the use of cannabis. Almost half (47%) said they had used drugs during their last anal sex encounter. Depressive symptoms were present in 45% of men and 43% had medium to high levels of internalised homophobia. Levels of substance use, depression and internalised homophobia did not differ according to HIV infection status.
After taking into account potential confounders, the investigators identified several factors associated with recent HIV infection.
Compared to men existing HIV infection, the newly diagnosed patients were younger (AOR = 2.9; 95% CI, 1.5-5.6). Comparison with HIV-negative men showed that recently diagnosed individuals were more likely to be unemployed (AOR = 2.6; 95% CI, 1.4-4.6); to have an STI (2.3; 95% CI: 1.4-4.0); to report unprotected receptive anal sex (AOR = 2.3; 95% CI: 1.4-3.8); and to have at least one HIV-positive partner (AOR = 3.8; 95% CI, 2.3-6.3).
“Since unprotected receptive anal intercourse was the major mode of HIV transmission among the men, studies on how best to promote sexual health among Black MSM are needed,” conclude the authors. “Further research designed to develop prevention interventions for Black MSM should also assess whether addressing socioeconomic, behavioral and broader health concerns may lead to decreases in HIV incidence in this heavily impacted population.”
Mayer KH et al. Concomitant socioeconomic, behavioral, and biological factors associated with the disproportionate HIV infection burden among black men who have sex with men in 6 U.S.cities. PLOS ONE 9 (1): e87298, 2014.