Gay men everywhere have
higher rates of HIV than in the general population, Fenton said. It is estimated that the
HIV rate in MSM is eight times that of the general population in low-income
countries and 23 times the general-population rate in high-income countries. The
most reliable prevalence figures suggest that, regionally, Latin America and the
Caribbean have especially high rates, but in no country of the world is HIV
prevalence lower in MSM than in the population as a whole. Even in South
Africa, the country with more people living with HIV than any other, HIV is
twice as common in MSM as it is in other people.
In the developed world,
the US has, by some way, the highest rate of HIV new diagnoses in MSM, though
the UK has possibly the highest current rate in Europe. However, in terms of the
rate of increase of new diagnoses, it
is central-European countries such as Poland, the Czech Republic and Hungary, historically
with very low prevalence, that are seeing the fastest-growing European epidemics in MSM.
In the lower-income
world, reliable estimates of incidence are harder to come by, but over the last
few years studies have found huge increases in HIV diagnoses in MSM in
countries ranging from Thailand and China through Kenya to Nicaragua and Peru.
The highest-ever annual HIV incidence recorded in a study comes from a
group of MSM in Kenya, where a quarter of those originally HIV negative had HIV
a year later. Unfortunately, African countries – and some in other areas of the world – initially denying
they had MSM at all or any HIV problem in them, are now responding to the
realisation that many people with HIV are MSM by introducing repressive measures such as
HIV was especially high, Fenton said, partly for biological reasons. It is now estimated that
anal sex is 18 times better at transmitting HIV than vaginal sex. The chance of
HIV being caught from having receptive anal sex once with a partner with a
detectable HIV viral load is about 1.4% or one in 71 encounters; but because
people have sex together more than once, the per-partner likelihood of catching HIV from a sero-different partner is, in gay men, about 40%.
Another factor in gay
men’s higher HIV prevalence, Fenton added, was that because gay men have more
partners and higher changeover rates, their sexual networks are more closely
connected: 25% of gay men diagnosed with HIV were members of a cluster that had
HIV viruses that were genetically identical, suggesting rapid transmission
within the network, compared with 5% of heterosexual people.
Gay men do not just
have more HIV for biological reasons, however, noted Fenton. The rates of
smoking (at 27 to 66%, according to area), recreational drug use, lifetime
depression (about 40%) and lifetime severe anxiety (at 20%) are all roughly
double in gay men what they are in the general population. Underpinning these
are higher rates of traumatic experience such as child sexual abuse (CSA) and
intimate partner violence (IPV).
In several studies that looked at rates of
depression, drug use, CSA and IPV in gay men, and related them to HIV prevalence
and high risk sex, gay men with three or four of these conditions were twice as
likely to have HIV and three times as likely to have had recent high-risk sex
than men with none of them.
disadvantage and racism also magnified the effects of HIV in MSM: this was one
of the reasons why black gay men in the US are three times more likely to have
HIV than white gay men.