Very high HIV incidence among men who have sex with men in Kenya

HIV incidence among men who have sex with men (MSM) in Kenya is as high as 35%, investigators report in the online edition of AIDS. Incidence was just 6% for bisexual men, but was 35% in men who only had sex with other men.

The study adds to the growing body of evidence showing the severity of the HIV epidemic among MSM in Africa.

“MSME [men who reported sex exclusively with men], who have been referred to as ‘queens’ in Kenya, experience very strong societal rejection and may face greater barriers than MSMW [men who reported sex with men and women] to accessing medical services,” comment the authors.

Group sex and recent infection with gonorrhoea were among the risk factors for acquisition of HIV.

Results also showed that men infected with HIV maintained viral loads associated with a high risk of HIV transmission for around three-quarters of the time during the two years after seroconversion, despite the fact that the majority were not eligible for antiretroviral treatment owing to having CD4 cell counts above 350 cells/mm³.

Same-sex behaviour is criminalised in Kenya and is also highly stigmatised. This is also the case in many other African settings. Recent research has shown that HIV prevalence among MSM equals or exceeds that seen in the general population in most sub-Saharan countries.

Investigators in Kenya wanted to establish a clearer understanding of the rate of new HIV infections among MSM. The researchers also wanted to see if HIV incidence differed between bisexual men and men who reported sex exclusively with other men. They also analysed the risk factors for infection with HIV and monitored the viral load of individuals who seroconverted for two years after their diagnosis.

Recruitment to the prospective study started in 2005. MSM were recruited via walk-in clinics in the costal towns of Mtwapa and Kilifi, or via personal contacts.

Participants were tested for HIV and other sexually transmitted infections (STIs) when they were recruited to the study. At this time, they also had face-to-face interviews with clinic staff about their sexual behaviour.  Follow-up was every three months.

A total of 449 HIV-negative MSM were recruited to the study. Of these, 372 (83%) reported sex with men and women. The remaining 77 men (17%) reported sex exclusively with other men.

Bisexual men were more likely to report insertive anal sex; exclusively homosexual men were more likely to report receptive anal sex (p < 0.001).

Overall, the men contributed 744 person-years of follow-up. The median duration of follow-up was 21 months for bisexual men, compared to 5 months for exclusively homosexual men (p 0.001).

In all, 64 men (9%) were infected with HIV. Incidence was 6% for bisexual men compared to 35% for men who exclusively had sex with other men (p < 0.001).

Factors associated with infection with HIV included: exclusive homosexual behaviour (aIRR = 3.7; 95% CI, 2.1-6.5); recent unprotected sex (aIRR = 2.1; 95% CI, 1.1-4.1); group sex (aIRR = 1.99; 95% CI, 1.0-3.4); and recent infection with gonorrhoea (aIRR = 14.7; 95% CI, 8.3-26.0).

Monitoring of viral load in the men who became infected with HIV showed that 75% of measurements were over 10,000 copies/ml in the two years after seroconversion. CD4 cell counts fell below 350 cells/mm³ on only 13% of study visits, indicating that the vast majority of infected men would not have qualified for antiretroviral therapy.

“The very high HIV-1 incidence among MSM from Coastal Kenya may be the result of studying interconnected networks of adults with ongoing high-risk sexual activity,” comment the investigators. “Interventions aiming to reduce HIV-1 acquisition and transmission among MSM in Kenya should include frequent, targeted HIV testing and linkage to care, with a strong focus on effective biomedical interventions such as pre-exposure prophylaxis (PrEP) and early ART.”