Mon 10 Mar 2014 In: Health and HIV View at Wayback View at NDHA
The NZAF and the Gay Men’s Sexual Health research group are advising caution over the latest results from a study into the risks of transmission where one partner is HIV positive, and taking effective HIV treatment. Updated findings from the PARTNER study group have been presented at the Conference on Retroviruses and Opportunistic Infections in Boston. They provide further evidence that treatment which effectively reduces viral load to undetectable levels has a protective effect against HIV for gay couples, where one of the two partners is uninfected. No linked HIV transmissions have occurred from HIV positive people on HIV treatment, who had a fully suppressed viral load, to their uninfected regular partner after one year of follow up. The study involves 586 heterosexual and 308 gay male couples who reported inconsistent condom use. The New Zealand AIDS Foundation is warning it would be dangerous to think about the latest information in overly simplistic terms. It points out that in New Zealand, men who have sex with men are the most at risk group from HIV transmission. One in five men living with HIV is not aware of his HIV positive status. Shaun Robinson “It is obvious that this study is in no way a replacement for condom based prevention on a wider scale,” NZAF Executive Director Shaun Robinson says. He cites research in the New England Journal of Medicine last month that only 25 per cent of people living with HIV in America are being treated to the point where they have undetectable viral load. “This means preventive effects in the PARTNER study are applicable only to a small subset of people living with HIV,” he says. "Members of the study’s own research team state that it does not guarantee or prove the safety of having sex without a condom when viral load is undetectable and we should all be very mindful of that." While the short term risk of passing on HIV if one partner has undetectable viral load appears to be low, the PARTNER study itself estimates the higher risk of this over time - at up to a 32 per cent chance of passing on HIV over 10 years to the HIV negative partner through receptive anal sex. "These are not good odds," Robinson says. “The ‘PARTNER’ study team warns that much more work is required to understand these risks. The NZAF’s advice to all gay men is to maintain the condom use that has kept HIV to low levels in New Zealand.” Dr Peter Saxton Director of the Gay Men’s Sexual Health research group Dr Peter Saxton echoes NZAF’s concerns and advises caution while interpreting the study. He says while the importance of an early diagnosis for managing someone’s HIV infection is well-known, it is becoming clearer that full viral suppression through treatment also reduces HIV transmission risk to others. “These interim results will provide relief for diagnosed, treatment adherent and fully virally suppressed HIV positive individuals and their partners who are anxious in the rare event of a condom breaking. The transmission risk will be very low should that occur,” Dr Saxton says. However he points out the study emphasises the much higher possible cumulative risk over time, which better approximates real-life relationships. For example, the study estimated the possible long term HIV transmission risk for HIV negative gay male partners engaging in receptive anal intercourse as being up to 32 per cent over 10 years. HIV treatment also provides no protection against other STIs, and 16 percent of the HIV negative gay men who weren’t using condoms acquired an STI over a median of 1.1 years of follow up. Dr Saxton said a concern is that some gay and bisexual men, who are at highest risk of HIV in New Zealand, might use these interim findings from a tightly monitored study population to justify “risk compensation”: abandoning condoms in favour of HIV treatment. “Gay and bisexual men will only experience the benefits of HIV treatment on controlling the HIV epidemic if condom use doesn’t deteriorate in response. The real world consists of repeated sexual acts, overlapping relationships, imperfect treatment adherence and awareness of actual HIV viral load, other STIs that are very serious but avoidable by condom use, and tightly knit communities where infection can spread very quickly,” Dr Saxton says. “In the face of such real life uncertainties condoms are effective and verifiable, so you’re not left wondering whether you’ve been put at risk, or have placed someone else at risk”. Dr Saxton says the situation currently facing gay and bisexual men is already very challenging with rising HIV and STI epidemics in many countries. “In New Zealand we’ve controlled HIV and STIs far better than most. Condom use needs to be maintained by everyone if these added benefits of HIV treatment are not to be squandered.” Dr Saxton adds “We also need to be very mindful that these preliminary study results don’t place either partner under pressure to cease condom use. That would be premature and unfair. So far what this represents is that treatment is an extra safety net, not a replacement for condoms.” Telling findings: • The study also estimates that over a ten year period a couple having sex only 45 times a year had up to a 9% chance of passing on HIV to the receptive HIV negative partner through anal sex and up to a 32% chance of passing it on through receptive anal sex. • Within relationships gay men in the study were having sex less than once a week . If couples have more frequent sex then the risks of transmission of HIV would be higher than in the study • HIV negative gay men in the trial were having unprotected sex outside of their relationship 34% of the time and as a result several people did contract HIV. Monogamy was far less common amongst the gay couples studied. Clearly a condom culture is still vital at a community level given this high rate of partner change. • If the person with HIV in the couple had not been on treatment and had a fully suppressed viral load, the study indicated that HIV would have been transmitted to 86 of the 154 gay men without HIV. So if adherence to medication is poor or viral load is not effectively or consistently suppressed, the risk of passing on HIV is considerable. • Gay men in the study also had greatly elevated rates of STIs (mainly gonorrhoea and syphilis) - 16% compared to 5% for heterosexuals in the study. Undetectable viral load for HIV gives no protection against any other serious STIs. GayNZ.com staff - 10th March 2014