CROI 2014A Seattle study has found that about 40 percent of HIV-negative gay men restrict their sexual partners to those they perceive to share their serostatus in an attempt to prevent acquiring the virus, aidsmap reports. Meanwhile, German researchers found that 10 percent of HIV-positive gay men consider themselves uninfectious if they have an undetectable viral load and take this belief into account when making choices about sexual behavior. Results from both studies were presented at the Conference on Retroviruses and Opportunistic Infections (CROI) in Boston.

The Seattle researchers conducted two separate questionnaires with 1,902 gay men accessing a local HIV/sexually transmitted infection clinic between February and August 2013. The first questionnaire asked about their recent sexual behavior, including use of condoms, HIV status of their partners and which role they played in intercourse, among other topics. The second questionnaire asked about what strategies they used to reduce their risk of HIV acquisition.

A total of 964 people completed both questionnaires, including 835 (87 percent) who were HIV negative and 129 (13 percent) who were HIV positive. Out of the HIV-negative men, 42 percent were “strict serosorters,” reporting only having sex, with or without condoms, with other HIV-negative men (39 percent reported this was a deliberate strategy). A total of 6.5 percent engaged in “condom serosorting,” reporting only having sex without a condom with other HIV-negative men (5.2 percent said this was a strategy). And a total of 7.1 percent were “seropositioning,” saying they only had sex without a condom if they were the insertive partner (the top), irrespective of the partner’s HIV status (6.5 percent said this was a strategy).

As for the HIV-positive men, 32 percent were strict serosorters, with 25 percent adopting this as a deliberate strategy. Eleven percent engaged in condom serosorting and 10 percent in seropositioning.

In the other study on this topic presented at CROI, German researchers questioned 269 gay men living with HIV about whether they considered themselves able to infect someone if they had an undetectable viral load. Ten percent reported believing themselves uninfectious with a fully suppressed virus and taking such a belief into consideration when making choices with regards to sex. A total of 57.5 percent of these “viral sorters” reported recent sex without a condom, compared with 36 percent of the men who were not viral sorters. Seventy percent of the viral sorters reported anonymous casual sex, compared with 44 percent of the non-viral sorters. And 19 percent of the viral sorters said they had recently divulged their HIV status, while 22 percent had recently discussed HIV at all. The respective figures for the rest of the men on these two counts were 42 percent and 44 percent.

To read the aidsmap story, click here.