HIV-negative Australian men who have sex with men (MSM) surveyed two years ago generally expressed a lack of comfort with the idea of having condomless sex with an HIV-positive man who was on antiretroviral (ARV) treatment and had an undetectable viral load, aidsmap reports.

Throughout the 2010s, a growing bodyof research has found that people with HIV, including MSM and heterosexuals, who have a sustained undetectable viral load, also known as a fully suppressed virus, do not transmit the virus to others through condomless sex. By 2017, the scientific evidence had reached such a critical mass that the Centers for Disease Control and Prevention (CDC) concluded that those with full viral suppression have effectively no risk of transmitting HIV to their sexual partners.

This new Australian study, which was published in Sexually Transmitted Infections and AIDS & Behavior, was conducted in August and September 2016. Although HIV treatment’s power to prevent transmission of the virus was certainly widely appreciated in the research community at that time, such awareness may have been more limited among MSM in general. Since 2017, activists, researchers, clinicians and others in the HIV community have stepped up efforts to communicate to the general public the scientific consensus that sustaining an undetectable viral load yields an extremely effective, likely even perfect, barrier against transmission of HIV.

In 2016, Australia also greatly increased promotion of pre-exposure prophylaxis (PrEP), including the launch of a massive study of the use of Truvada (tenofovir disoproxil fumarate/emtricitabine) as HIV prevention among MSM at high risk of contracting the virus in the state of New South Wales. Within just one year of the study, the rate of diagnoses of recently acquired cases of HIV among all MSM in the state as a whole dropped by an impressive one third. Researchers concluded that PrEP was the driving factor behind this sudden shift.

The new online survey of 844 MSM was conducted in Melbourne and elsewhere in the Australian state of Victoria. Half of the men were between 25 and 40 years old. Most identified as gay. One in three reported having condomless sex with a casual partner during the previous six months, half of them with a regular partner.

The study authors excluded from their analyses men living with diagnosed HIV. They looked at responses from 771 men who had been diagnosed as HIV negative or had not been tested for the virus—including 83 men (12 percent of the group) taking PrEP—regarding how comfortable they felt about the notion of having condomless sex in particular contexts. Analyses about the men’s perception of the effectiveness of PrEP and HIV treatment as prevention of the virus focused on responses from 462 HIV-negative men who were not taking Truvada for prevention.

Seventy-eight percent of non-PrEP users agreed that “PrEP is effective in preventing HIV infection,” while 65 percent agreed that “an HIV-negative person who is on PrEP is unlikely to get HIV.” Seventy-four percent agreed that PrEP users were “being responsible,” while 84 percent said such individuals were “protecting themselves.”

Eighteen percent agreed that “a person with an undetectable viral load cannot pass on HIV,” and 20 percent agreed that “an HIV-positive person on treatment is unlikely to transmit the virus.” Thirty-seven percent agreed that “if more HIV-positive men have an undetectable viral load, then I’m less likely to get HIV,” while 82 percent agreed that “HIV-positive people should go on treatment to protect their partners.” 

Eighty-four percent agreed that people with HIV “should start treatment [for the virus] as soon as they are diagnosed.” Fewer than 1 in 10 of respondents supported statements suggesting that people with HIV should delay starting ARVs until they are ready or until treatment is imperative.

Sixteen percent agreed that “if more men are on PrEP, I would feel like I don’t need to use condoms to avoid getting HIV,” while 12 percent agreed that “because of PrEP and HIV treatments, I’m less likely to ask my partners about their HIV status.”

In fact, a different study recently found that the rapid upswing in PrEP use in Australia between 2016 and 2017 was associated not only with a declining condom use rate among MSM on PrEP but also among HIV-negative non-PrEP users.

Among those not taking PrEP in the new survey study, 7 percent said they were generally comfortable with the notion of  having condomless sex with any casual partner, while 5 percent would be with a casual partner whose HIV status was unknown, 3 percent would be with a casual partner who was HIV positive, 6 percent would be with an HIV-positive partner who had an undetectable viral load, 31 percent would be with a casual partner who said he was HIV negative and 23 percent would be with an HIV-negative man who was on PrEP.

Of the 83 men taking PrEP, a respective 72 percent and 64 percent were comfortable with the idea of having condomless sex with other PrEP users and with HIV-negative men not on PrEP. A respective 29 percent, 34 percent and 40 percent of PrEP users were comfortable with the idea of having condomless sex with an HIV-positive partner, a partner of unknown HIV status and any casual partner. Forty-eight percent would be comfortable with condomless sex with an HIV-positive partner who had a fully suppressed viral load.

To read the aidsmap article, click here.

To read the study abstract, click here.