More HIV-negative men are having unprotected sex in primary relationships, but not all of them know their partner’s status

Continuing an upward trend seen over a decade, 36% of the men taking part in the 2008 London gyms study had had unprotected anal intercourse in the previous three months, researchers report in an article published online ahead of print in Sexually Transmitted Diseases. However this overall increase “masks a more complex picture” concerning the HIV status of men’s partners, the researchers say.

More unprotected sex now occurs with partners of the same status than with men of unknown or different HIV status. Moreover, there has been an increase in the number of men reporting unprotected sex with a main partner whose HIV status is unknown or different.

Since 1998 an annual survey has been conducted at London gyms which are popular with gay men. The survey was conducted annually from 1998 to 2005 inclusive and then finally in 2008, when 648 men took part.

Amongst other things, men were asked if they had had unprotected anal sex in the previous three months and to specify if this was with a main or casual partner. They were also asked to provide details of their own HIV status and to say if they knew the HIV status of the partner(s) with whom they had unprotected anal sex.

When the study was first conducted in 1998, 24% of men reported recently having unprotected anal intercourse (UAI), a figure which rose to 36% in 2008.

However both in the 2005 and 2008 surveys, more men reported having unprotected sex with men of the same HIV status as themselves (“serosorting”) than with men of unknown, assumed or different HIV status. To put this in figures, in 2008, 21% reported UAI with men of the same status and 16% reported UAI with men of unknown, assumed or different status.

Among HIV-positive men, 14% serosorted with casual partners in 2008. Whereas the number of men reporting this behaviour had been increasing in previous surveys, it was lower in 2008 than in 2005. Moreover, 10% of HIV-positive men had unprotected sex with a main partner who was also HIV positive.

Among men who reported that their last HIV test was negative, less than 2% serosorted with casual partners. However 21% had unprotected sex with a main partner whose last HIV test was also negative. The proportion reporting this behaviour has been increasing since the first survey in 1998, when 12% reported it.

The researchers express concern about the means by which HIV-negative men establish that their main partner has the same status. Whereas four in ten tested together, the others talked about their status. The authors consider this unsatisfactory as the accuracy of the information shared will depend on the time since the last test and on subsequent risk behaviour.

Turning now to unprotected sex with partners whose HIV status may be different, primary relationships appear to be where an increasing amount of risk taking is occurring, although absolute figures remain low.

Comparing the 2005 and 2008 surveys, there have been significant increases in the numbers of men reporting having unprotected sex with a main partner of unknown, assumed or different HIV status.

Among HIV-negative men, 2.1% reported this in 2005, rising to 5.5% in 2008. In almost all cases, the partner’s HIV status was unknown or assumed to be the same, rather than known to be different.

Among HIV-positive men, 2.5% reported this in 2005, rising to 8.1% in 2008. In approximately half these cases, the partner’s HIV status was known to be HIV-negative.

Turning to unprotected sex with casual partners of an unknown or assumed HIV status, a significant proportion of HIV-positive men (19%) report this, although this figure is much lower than in surveys earlier in the decade.

Fewer than 6% of HIV-negative men report this behaviour, the lowest level reported in any of these gym surveys. The researchers comment: “This is an encouraging trend and is likely to reflect consistent and sustained health promotion campaigns targeting gay men.”

Summing up, the researchers say that their data “suggest that main partners may have become an important source of HIV risk among London’s gay men.” They recommend that more health promotion campaigns should focus on HIV risk within relationships and on HIV testing among couples.

Lattimore S et al. Changing Patterns of Sexual Risk Behavior Among London Gay Men: 1998–2008. Sex Transm Dis 2010 doi: 10.1097/OLQ.0b013e3181f2ebe1