Different HIV rates among gay men and straight people not fully explained by sexual behavior

Sep 13, 2007

Differences in sexual behaviours do not fully explain why the US HIV epidemic affects gay men so much more than straight men and women, claims research published ahead of print in the journal Sexually Transmitted Infections.

In 2005, over half of new HIV infections diagnosed in the US were among gay men, and up to one in five gay men living in cities is thought to be HIV positive.

Yet two large population surveys showed that most gay men had similar numbers of unprotected sexual partners per year as straight men and women.

US researchers applied a series of carefully calculated equations in different scenarios to study the rate at which HIV infection has spread among gay men and straight men and women.

They used figures taken from two national surveys to estimate how many sex partners gay men and straight men and women have, and what proportion of gay men have insertive or receptive anal sex, or both.

They then set these figures against accepted estimates of how easily HIV is transmitted by vaginal and anal sex to calculate the size of the HIV epidemic in gay men and straight men and women.

The results showed that for the straight US population to experience an epidemic of HIV infection as great as that of gay men, they would need to average almost five unprotected sexual partners every year.

This is a rate almost three times that of gay men.

But to end the HIV epidemic, gay men would need to have rates of unprotected sex several times lower than those currently evident among the straight population. This is because transmission rates are higher for anal sex than they are for vaginal sex, say the authors.

But "role versatility," whereby people adopt both “insertive” and “receptive roles,” also plays a part, they add.

A gay man can be easily infected through unprotected receptive sex, and then infect someone else through insertive sex.

Gay men are therefore far more susceptible to the spread of the virus through the population, even with the same numbers of unprotected sexual partners.

Source: BMJ Specialty Journals

Explore further: Poland suffers first cases of African swine fever in pigs

add to favorites email to friend print save as pdf

Related Stories

Eco-pottery product from water treatment sludge

23 minutes ago

Sludge is a by-product of water treatment. Sludge is produced during the clarification and filtration process in the water treatment system. It is also produced from the accumulated solids removed from sedimentation ...

Brand new technology detects probiotic organisms in food

23 minutes ago

In the food industr, ity is very important to ensure the quality and safety of products consumed by the population to improve their properties and reduce foodborne illness. Therefore, a team of Mexican researchers ...

Recommended for you

Experts call for stepped-up hepatitis battle

5 hours ago

The world can beat the cancer-causing disease hepatitis if it raises its game, but treatment programmes need to go hand in hand with those tackling the likes of HIV, experts said Thursday.

User comments : 0