Promoting 100% condom use may not be the most appropriate HIV prevention strategy for serodiscordant couples, according to research presented to the Fifteenth Conference of the British HIV Association. However, researchers found that there was little awareness or use of other methods of HIV prevention, such as post-exposure prophylaxis (PEP) or the impact of viral load on infectiousness.
Investigators recruited 38 serodiscordant couples (where one partner is HIV-positive, the other HIV-negative) to a prospective study lasting three years. Most (30) of the couples were gay men. To be included in the study the couples had to have been in their relationship for at least two years and to have engaged in at least 20 separate episodes of unprotected anal or vaginal sex in the previous twelve months.
The couples were interviewed about their understanding of issues such as PEP, viral load and infectiousness, and the reasons why they engaged in unprotected sex. The investigators hypothesised that there were likely to be three factors underlying unprotected sex in relationships: failure to understand the mechanisms of HIV transmission; emotional reasons; and a low concern about the consequences of HIV transmission.
There was a very low awareness of the availability of PEP, a short course of antiretroviral treatment that is taken after exposure to HIV to prevent infection. Only 16% of HIV-negative partners and 32% of HIV-positive partners were aware of its availability. Only one couple reported ever having used PEP. One HIV-positive woman was circumspect about the value of PEP, telling the investigators that the frequency with which she and her partner engaged in unprotected sex would mean that “he’d need it every week.”
Nor was there an understanding of the impact of viral load on infectiousness.
Nevertheless, the couples did report the use of some strategies to try and reduce the risk of HIV transmission. In gay couples, this included the HIV-negative partner being insertive, and most HIV-positive men reported never ejaculating inside their partner when having unprotected sex.
But unproved risk reduction strategies were also being used; one man expressed the belief that masturbation a couple of days before unprotected intercourse cleared infectious HIV from semen; another individual told the investigators that he thought that transmission was not possible if he had a high CD4 cell count.
Generally, the HIV-positive partner was more concerned about the risk of transmission than the HIV-negative one. Emotional reasons were a key factor, with individuals reporting that intimacy and trust were important reasons for unprotected sex. However, one African woman said that in her relationship and culture it was not possible for a woman to refuse sex to her husband.
Dislike of condoms was another widely reported reason for unprotected sex. Others said that condoms caused erectile dysfunction or were a reminder that HIV was present in the relationship. However, some couples told the investigators that they had never discussed the reasons for not using condoms.
HIV-negative rather than HIV-positive partners were generally more sanguine about the consequences of HIV transmission occurring. One HIV-negative man said that, “Sooner or later there is going to be a cure”. Nor, according to the HIV-negative study participants, would there be blame if transmission occurred. One HIV-negative man told the researchers, “It would upset him more than me,” while his partner said, “If he becomes positive because of me, I don’t know how I’d deal with it”.
The investigators also found evidence that HIV-negative partners felt isolated and were unsure where they could discuss their experiences with individuals in a similar situation.
“A blanket healthcare message of safe sex seems inappropriate for all HIV serodiscordant couples,” comment the investigators, “provision of an open discussion of risk and identification of barriers to condom use may be more meaningful than promoting a 100% condom approach.” The investigators suggest that the statement by leading Swiss HIV doctors in early 2008 that, in certain circumstances, individuals taking antiretroviral therapy with an undetectable blood viral load were not infectious to their sexual partners offered one possible approach.
However, separate research presented to the conference by investigators from the sperm washing unit at the Chelsea and Westminster Hospital, London, showed that 10% of men with an undetectable blood viral load had “significant” viral load in their semen. When challenged to define significant, the presenting investigators said that this meant that HIV could be detected, but were unable to say if potentially infectious quantities of the virus were present.
Fox J et al. Understanding of HIV-risk behaviour in HIV-serodiscordant couples – a novel approach. Fifteenth Annual Conference of the British HIV Association, abstract P149, Liverpool, 2009.
Nicopoullous JDM et al. A decade of the sperm-washing progam: the effect of HIV on semen parameters and viral load? Fifteenth Annual Conference of the British HIV Association, abstract o8, Liverpool, 2009.