HIV-negative gay men uncomfortable relying on an undetectable viral load to prevent HIV

Australian HIV-negative gay men express far more confidence in pre-exposure prophylaxis (PrEP) than an undetectable viral load in preventing HIV, with only 18% agreeing that “a person with an undetectable viral load cannot pass on HIV” and 6% feeling comfortable having condomless sex with an HIV-positive partner who had an undetectable viral load, according to a pair of articles recently published in Sexually Transmitted Infections and AIDS & Behavior.

Confidence in the efficacy of PrEP was much higher.

Researchers from the Burnet Institute conducted an online survey with gay and bisexual men living in Melbourne and other parts of the state of Victoria. It included a series of questions to gauge men’s knowledge of and attitudes towards condoms, an undetectable viral load and PrEP.

Australia has a long history of promoting condom use and regular HIV testing in gay men. More recently, there has also been high-profile support for treatment as prevention and PrEP. Around the time the survey was conducted in August and September 2016, a PrEP demonstration project was scaling up in Victoria. Several Australian campaigns promoting the benefits of HIV treatment had already been run, but the international "Undetectable = Untransmittable" campaign had not yet taken off. 

Half the survey participants were between the ages of 25 and 40; most identified as gay; and 20% were born outside Australia. A third reported condomless sex with a casual partner in the past six months, and half with a regular partner.

The survey was completed by 844 people, but men with diagnosed HIV were excluded from the following analyses. The data on comfort having condomless sex come from 771 HIV-negative or untested men, including 83 PrEP users (12% of the men). The data on perceptions of effectiveness come from a smaller group of 462 survey respondents who answered all relevant questions and were not using PrEP. (The researchers did not report on responses from PrEP users for these questions.)

Perceptions of effectiveness

Although this analysis excluded current PrEP users, the majority of respondents expressed confidence in PrEP’s effectiveness: 78% agreed that “PrEP is effective in preventing HIV infection” and 65% agreed that “An HIV-negative person who is on PrEP is unlikely to get HIV”. Respondents also agreed that PrEP users were “being responsible” (74%) and were “protecting themselves” (84%).

In contrast, 18% agreed that “A person with an undetectable viral load cannot pass on HIV”. A similar statement, with less definitive language was not much more popular – 20% agreed that “An HIV-positive person on treatment is unlikely to transmit the virus”.

Despite this scepticism, other findings showed that respondents were aware that HIV treatment has a prevention impact – 37% agreed that “If more HIV-positive men have an undetectable viral load, then I'm less likely to get HIV” and 82% agreed that “HIV-positive people should go on treatment to protect their partners”.

Moreover, taking treatment soon after diagnosis appears to have become a community norm – 84% agreed that “People should start treatment as soon as they are diagnosed”, while statements suggesting that people should delay until they are completely ready or until treatment is absolutely necessary were supported by fewer than 10%.

This cohort of HIV-negative men generally rejected relying on their partners using antiretrovirals in order to be protected from HIV. They suggested that their personal sexual strategies would not change in response – 16% agreed that “If more men are on PrEP, I would feel like I don’t need to use condoms to avoid getting HIV”. Similarly, 12% agreed that “Because of PrEP and HIV treatments, I'm less likely to ask my partners about their HIV status”.

Comfort having condomless sex

Men were asked, “How comfortable would you be having anal sex without a condom with casual partners in the following scenarios?” and were asked to respond for a number of partner types. There were important differences between the responses of PrEP users and non-users.

The 668 men who were not taking PrEP were generally uncomfortable with the idea of having condomless sex – only 7% said they would be comfortable doing so with ‘any casual partner’, 5% with a casual partner of unknown HIV status and 3% with an casual partner who was HIV positive.

It made little difference if the HIV-positive partner had an undetectable viral load – 6% would feel comfortable having sex with him.

Men appeared to be more comfortable serosorting, although this can be a risky strategy for HIV-negative men as there is always the possibility that a partner has recently acquired HIV but has not yet been diagnosed. Among men not using PrEP, 31% said they would be comfortable having condomless sex with a casual partner described as HIV negative. If the same man was taking PrEP, fewer men (23%) would be comfortable having condomless sex with him, perhaps reflecting a perception of PrEP users as risk takers.

The 83 respondents who were using PrEP were more comfortable with the idea of having condomless sex, but comfort levels were not particularly high.

PrEP users were most likely to feel comfortable having condomless sex with other HIV-negative PrEP users (72%) and HIV-negative partners not taking PrEP (64%).

The proportion who would feel comfortable having condomless sex with an HIV-positive partner (29%) was lower than for a partner of unknown HIV status (34%) or ‘any casual partner’ (40%).

And less than half of current PrEP users would be comfortable having condomless sex with an HIV-positive partner with an undetectable viral load (48%), although the respondent would be protected by two extremely effective prevention methods.

Conclusions

“While gay and bisexual men are highly supportive of pre-exposure prophylaxis, there remains some scepticism towards HIV treatment when used for prevention,” sum up the authors. “Increasing community understanding of treatment as prevention is needed to optimise treatment-based HIV prevention strategies.”

“In general, HIV-negative and untested gay and bisexual men indicated that they remained more comfortable negotiating condomless sex based on knowledge of HIV status, rather than PrEP or undetectable viral load.”

Many men continue to rely on serosorting: “HIV-negative men tend to perceive all sex with HIV-positive partners as potentially risky, regardless of condom use, HIV treatment or viral load.”

Some commentators have suggested that PrEP and understanding of undetectable viral loads could help reduce HIV stigma and the fear of partners living with HIV. However, PrEP users’ relatively high levels of discomfort with the idea of condomless sex with HIV-positive partners suggest that these hopes may be over-stated, the authors comment.