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
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.”