NAPWA

Girlfriend! Have you heard the excellent news from Switzerland? Apparently a group of Swiss boffins have declared that you can't transmit HIV if you have undetectable viral loadA measurement of the quantity of HIV RNA in the blood. Viral load blood test results are expressed as the number of copies (of HIV) per milliliter of blood plasma.! Bareback sex is now officially safe! Surely this is the best thing to come out of Switzerland since the naked fondue party!

Well, sort of.

It's true that a group of Swiss AIDS experts have issued a ‘consensus statement' declaring what many of us suspected but nobody – at least nobody in such a position of authority – had dared say before. If you're positive, on treatment with undetectable viral load and have no STIs[Sexually Transmissible (or Transmitted) Infection] Infections spread by the transfer of organisms from person to person during sexual contact. Also called venereal disease (VD) (an older public health term) or sexually transmitted diseases (STDs). , there's no evidence you can transmit HIV through sexual intercourse.

As you can imagine, this announcement came as something of a shock, especially to the ‘abstinence is the only safe sex' brigade in the US, who have reacted with predictable panic. These are the people who've never quite accepted that anal sex with a condom is really safe, so I guess that's to be expected, but in any case, the Swiss announcement has put the cat among the pigeons for AIDS educators around the world.

In Australia, the reaction has been a little more tame, but still cautious. In the last few weeks there's been a lot of discussion within the HIV sector about the implications for HIV prevention, for HIV treatment and for people living with HIV.

So, is it true? Could, say, an HIV-positive gay man fucking an HIV- negative gay man without a condom really be considered ‘safe sex'?

First, some background: lots of people have been referring to this as ‘the Swiss study', which is misleading, as the researchers involved didn't carry out a specific trial. Instead, they reviewed previously published clinical trials, academic papers and other evidence from the scientific literature. In this article we'll refer to the published article as ‘the Swiss statement'.

The statement was issued on behalf of the Swiss Federal Commission for HIV/AIDS and was written by four eminent HIV-specialist physicians. Importantly, this isn't a crackpot theory cooked up by some lunatic fringe AIDS denialist – the authors of the Swiss statement are respected physicians with a wealth of experience in their field.

Based on their review, the authors declared “An HIV-infected person on antiretroviralA medication or other substance which is active against retroviruses such as HIV. therapy with completely suppressed viraemia (‘effective ART') is not sexually infectious, i.e. cannot transmit HIV through sexual contact.”

As you'd expect with a statement as seemly heretical as that, there are a number of provisos. The statement argues that positive people are sexually non-infectious only if:

1. They're on orthodox multi-drug treatment (HAARTHighly Active AntiRetroviral Therapy ??? aggressive treatment of HIV infection using several different drugs together.), highly adherent (taking all prescribed doses on time) and their treatment is regularly evaluated by the treating doctor;
2. Their viral load has been consistently undetectable (less than 40 copies/ml) for at least six months; and
3. They have no other sexually transmissible infections (STIs).

If you just read that list and thought ‘well, that sounds like me' you'll want to know that Australian HIV sector organisations are treating the Swiss statement with caution and have argued that this development shouldn't be used as a justification for changing sexual practices. In other words, don't ditch the condoms just yet.

There are, however a number of issues thrown up by the Swiss statement, and some intriguing possibilities for a change in our understanding of what constitutes safe sex, if not immediately then perhaps in the future.

The publication of the Swiss statement led to a range of responses around the world, from the cautious ‘steady-as- she-goes' approach we've seen in Australia to a rather more panicked response (and a subsequent community outcry) in the US.

There are a number of important theoretical and methodological concerns with the Swiss statement that need to be mentioned.

Firstly, there is the difficulty (acknowledged by the authors) of proving a negative hypothesisA supposition or assumption advanced as a basis for reasoning or argument, or as a guide to experimental investigation. – proving that something is ‘impossible'.

Let's imagine we tried to prove that HIV-positive people with undetectable viral load can'tcouldn't transmit HIV through sex, as the Swiss have argued. If we did a study with 100 serodiscordant couples (one HIV-positive, one negative) over a period of one year, and no new infections occurred, we still wouldn't be able to say that it's impossible for HIV to be transmitted, only that there's no evidencethat it could. We could increase the number of participants, but no matter how many people we enrolledThe act of signing up participants into a study. Generally this process involves evaluating a participant with respect to the eligibility criteria of the study and going through the informed consent process., we still wouldn't be able to prove that infection is impossible in these circumstances.

“The situation is analogous to 1986, when the statement ‘HIV cannot be transmitted by kissing' was publicised,” they wrote. “This statement has not been proven, but after 20 years' experience its accuracy appears highly plausible.”

A second criticism relates to the fact that the studies the researchers based their conclusions on were focused on vaginal intercourse, throwing into question their relevance for gay men, who continue to make up the majority of the Australian HIV-positive population.

The authors acknowledged that the risk of HIV transmission is generally higher for anal compared to vaginal intercourse, however they believe this difference is insignificant when viral load is effectively suppressed – in other words, if having undetectable virusA small infective organism which is incapable of reproducing outside a host cell. makes you non-infectious for vaginal sex, there's no biological reason why the same wouldn't be true for anal sex.

Thirdly, some critics have noted that we already have numerous case reports of people who contracted HIV from someone they believed had undetectable viral load. In a recent Australian study of newly infected gay men, nine of 143 participants said the source of their infection was a man with undetectable viral load.

The researchers argue that research of this kind, while useful, cannot be relied on when trying to determine the science behind HIV trans- mission, as it is coloured by individual misunderstanding, miscommunication and a lack of willingness for people to be honest about their sexual activities to researchers.

“Anecdotes regarding HIV infection are inherently problematic, because their interpretation depends on what people tell you about their sex lives,” they wrote. “Unfortunately, one cannot rely on this kind of information.”

Putting it all together

What are the implications of this for Australian gay men with HIV?

Firstly, it's important to acknowledge that nothing (much) has changed. We already knew that having undetectable viral load reduced your risk of infecting your partner – this has been acknowledged in the scientific literature for years, and is routinely used as a (very valid) reason to encourage sexually-active people with HIV to take up treatment. And it's worth repeating that, Swiss statement or no Swiss statement, the best way to prevent HIV transmission is and always will be to use a condom.

But Australian gay men have proven themselves adept in adopting other risk reduction strategies to help reduce their risk of HIV transmission, whether or not they use condoms. Seeking out partners of the same HIV status (‘sero- sorting'), taking the bottom role in anal sex (‘strategic positioning') and modifying choices based on what you know about your viral load are some of these strategies which have been much discussed in recent years.

If you're having casual sex, it's probably too early to rely on undetectable virus alone to protect your partner. Condoms and other risk reduction strategies are still the best approach. You can take comfort in the fact that, if your viral load is undetectable, the risk of passing on HIV is very low (of course we already knew that) – condoms still break from time to time, misunderstandings occur and, in the heat of the moment, occasionally we do things we might normally not.

The Swiss statement should encourage all of us to be more active in preventing STIs, as these unquestionably increase the risk of transmitting HIV. Syphilis, gonorrhoea and Chlamydia are at record levels in the gay community right now, and HIV-positive men are disproportionately affected. If you're sexually active and haven't had an STI check-up in the last six months, ask your doctor for one.

Reducing STIs among gay men (especially pos men) would undoubtedly have a marked impact on new HIV infections. An increased emphasis on STI screening is needed, as is investigation of the viability of STI prophylaxis among positive men at high risk of contracting STIs.

Additionally, this statement gives us another reason to embrace HIV treatment, as it shows how going on treatments doesn't just protect our health, but the health of our sexual partners. While we're not ready yet to say people on treatment are non-infectious, the flipside – that people not on treatment and with detectable viral load are more infectious – is clear. If you're not on treatment, you really need to practise safe sex.

For people in long-term relationships, the Swiss statement does open up the possibility of a new form of ‘negotiated safety' for gay men. In an article on the gay men's health website LifeLube.org, Australian researcher Michael Hurley suggests that the Swiss statement could lead to the development of a new version of ‘Talk, Talk, Test, Trust' for gay men in serodiscordant relationships, based on clear agreements about treatments adherence, regular viral load monitoring, and STI prevention.

Will the Swiss statement mark a significant change in safe sex practice? Are we approaching a time when the condom is, if not an artefact of a bygone era, then at least just one part of our armoury against HIV?

We don't know yet, but the authors of the statement should be applauded for starting the conversation.

AUTHOR'S NOTE: Because the Swiss statement was published only recently, our community's response to it is evolving. For that reason, the opinions in this article are the author's own and do not reflect the view of NAPWHA.