Men who have sex with men (MSM) who have more sexual partners are more likely to use a variety of sexual risk reduction practices such as asking a partner about his HIV status before sex or preferring certain sexual positions over others. While having more sexual partners increases the risk of transmission of HIV, engaging in other risk reduction strategies, even those outside of the use of condoms, may otherwise reduce overall risk.

Those with more partners were also more likely to take illegal drugs, including ecstasy and crystal meth, and to exchange sex for money. Drug use can raise the risk of HIV transmission. HIV transmission risk is high among those trading sex for money.

Publishing their findings in AIDS Behavior, researchers from the Momentum Health Study, a prospective biobehavioral cohort study, recruited 719 MSM from Vancouver between February 2012 and February 2014.

The study predates the approval of Truvada (tenofovir/emtricitabine) as PrEP in Canada. So that risk reduction method was not taken into account.

A total of 76.7 percent of the participants were HIV negative or did not know their HIV status; the remainder were HIV diagnosed.

When entering the study, the participants responded to yes-or-no questions about risk reduction strategies for HIV transmission and acquisition, including whether they: always used condoms for anal sex; avoided anal sex; and asked sexual partners about their HIV status before sex.

The HIV-negative participants were asked if to reduce HIV risk, they used: strategic positioning (being the top for anal sex); serosorting (having anal sex without condoms only with men known to be HIV negative); viral load sorting (having anal sex without condoms with HIV-positive men who have low viral loads or who are on treatment for the virus); and withdrawal (not letting sex partners ejaculate inside of them).

The men living with HIV were asked if they used: strategic positioning (being the bottom for anal sex), serosorting (having anal sex without condoms only with men known to be HIV positive) and withdrawal (not ejaculating inside of partners).

A total of 65.1 percent of the men reported engaging in insertive anal sex (being a top) during the previous six months, while 63.5 percent reported having receptive anal sex (being the bottom) during this time frame.

In their analysis of the survey responses, the researchers divided the participants into two groups: the 195 men who reported having at least seven sexual partners during the previous six months (a quarter of the participants) and 523 men who reported six or fewer sexual partners during the same period (the remaining three quarters of the men).

Among the men who were not diagnosed with HIV, a respective 70.6 percent of men with seven or more recent sexual partners and 56.3 percent of the group of men with fewer sexual partners reported asking for partners’ HIV status before sex. In addition, a respective: 62.8 percent and 67.2 percent reported always using condoms; 36.5 percent and 18.7 percent reported strategic positioning; 32.3 percent and 30.2 percent reported serosorting; 27.2 percent and 22.2 percent reported withdrawal; 25.2 percent and 47.8 percent reported abstaining from anal sex; and 17.6 percent and 5.4 percent reported HIV treatment or viral load sorting.

Among the HIV-diagnosed men, between those with seven or more recent partners and those with fewer recent partners, a respective: 68.8 percent and 35.7 percent reported serosorting; 49.9 percent and 31.1 percent reported asking about a partner’s HIV status before sex; 48.8 percent and 22.2 percent reported treatment or viral load sorting; 47.6 percent and 24.4 percent reported strategic positioning; 38.7 percent and 38 percent reported avoiding anal sex; 34.2 percent and 25.1 percent reported withdrawal; 26.6 percent and 37.6 reported always using condoms; 19.3 percent and 30.4 percent reported condomless sex, but only with other HIV-positive men; and 75 percent and 30 percent reported condomless sex with HIV-negative men or men of an unknown HIV status.

After adjusting the data for various factors, the researchers found that among those not diagnosed with HIV, those with seven or more recent sexual partners, compared with those with fewer partners, were: 3.81 times more likely to use strategic positioning; 2.15 times more likely to ask about a partner’s HIV status before sex; 2.75 times more likely to prefer being versatile in sex (being the top or bottom) as opposed to being the bottom; 3.85 times more likely to identify as gay compared with bisexual or “other”; 3.13 times more likely to have greater than a high school education; 2.96 times more likely to report taking ecstasy during the previous six months; 2.78 times more likely to engage in water sports (the use of urine during sex); 6.07 times more likely to attend a group sex event during the previous six months; 5.35 times more likely to exchange sex for money during the previous six months; and 78 percent less likely to avoid anal sex.

In their analysis of the HIV-diagnosed men, the researchers found that those with seven or more recent partners, compared with those with fewer partners, were: 3.1 times more likely to ask about HIV status before sex; 1.17 times more likely to have higher scores on the Sexual Sensation Seeking scale, a “measure of the propensity to seek out novel or risky sexual stimulation," for every 1 unit of increase on the scale; 3.06 times more likely to report using crystal meth during the previous six months; 3.41 times more likely to have attended a group sex event during the previous six months; 5.07 times more likely to have exchanged sex for money during the previous six months; and 6.25 times more likely to have a greater preference for being sexually versatile versus being the bottom for sex.

The researchers concluded that their findings suggest “that these men are taking steps that are at least perceived to improve their sexual health and reduce HIV transmission while balancing their needs for sexual intimacy and pleasure.”

The study authors encouraged future research to determine the HIV prevention efficacy of the various risk reduction strategies explored in the study, how MSM perceive the efficacy of such strategies and “to determine the social and health impacts of widespread uptake of these strategies.”

The authors continued: “Each of these suggested areas remain important because, even if these strategies were sufficiently effective to prevent seroconversion [contracting HIV], they are by no means universally employed, and confusion regarding their efficacy is almost certain to continue. Though these strategies are more common among those with more sexual partners, they may not be used, nor understood, at sufficiently high rates to reduce population-level HIV incidence. Yet still, we do not know what widespread uptake of these strategies might mean for condom use, which is still regarded among the most efficacious prevention strategies. Finally, we note that these strategies are not necessarily effective in combating other STIs, which may put [MSM] at increased risk for HIV transmission or acquisition.”

To read the study abstract, click here.