Dr Joseph Sonnabend has an excellent critique of the iPrEx trial, the use of oral Truvada as pre-exposure prophylaxis (PrEP) against HIV. PrEP is the use of antiretroviral drugs in HIV negative people who are considered to be at high risk of infection. The trial achieved a 44% success rate, which is disappointing, but it's best to read Dr Sonnabend's critique if you're interested in a more balanced account of the trial than you'll find in the mainstream press or in the academic literature.
One of the many interesting points in the article, however, is not about PrEP, it's about HIV prevention interventions that aim to reduce HIV transmission by influencing people's sexual behavior. I have always objected to the view that HIV is almost entirely a result of 'unsafe' sexual behavior in African countries. So this means that I also feel a lot of behavioral interventions are not, despite claims to the contrary, contributing significantly to reductions in HIV transmission.
Dr Sonnabend argues that "If prevention education has been a failure, it’s not because it doesn’t work, but because we have not provided it well enough. There has been too little and most has not been properly targeted."
It's important to note that Dr Sonnabend is not writing about Africa, he is writing about a US, urban context. But what he says about behavioral interventions not being provided well enough is, I think, true of Africa too. And it is only now that PrEP is being bandied about as the solution to the HIV pandemic that others who promoted behavioral interventions in the past are beginning to question their effectiveness.
I am not opposed to behavioral interventions per se, I just haven't heard of any that have been particularly successful in reducing HIV transmission in Africa. But I think exercising some restraint over partner choice, number of partners, unprotected sex, age of sexual debut, unplanned pregnancy and many other things, is important. I also think these measures are important regardless of whether HIV is an issue.
However, in the African context, targeting could refer to two very different issues. The first issue in African countries with high HIV prevalence, I would argue, is not that some people have a lot of 'unsafe' sex but that many people are not being infected sexually. If people being infected sexually can be targeted and can be subjected to appropriate behavioral interventions, that should reduce sexual transmission of HIV.
But as things stand, with the assumption that most HIV is transmitted sexually, there is virtually no targeting. Everyone who has sex is considered to be at risk and anyone who is infected is considered to have engaged in 'unsafe' sex. This is despite plenty of evidence that non-sexual modes of HIV transmission are contributing significantly to African epidemics. Non-sexual modes of transmission need quite different types of intervention.
You might think that those most at risk of sexually transmitted HIV, such as sex workers and men who have sex with men, would be targeted in African countries because of their levels of sexual exposure. This a second kind of targeting issue, but these groups are almost completely ignored by HIV programming. That's unless you count the self-righteous rhetoric, which needn't cost very much.
Also in relation to behavioral interventions, Dr Sonnabend makes an observation about condoms that is missing from any of the prevention literature I have seen:
"Condoms can be a barrier to intimacy which for many is the most essential aspect of sexual intercourse, for both receptive and insertive partners. So recommending the use of condoms without acknowledging the significant obstacle they may present to a fulfilling sexual experience is a real problem. Pleasure is part of that fulfilment and for some insertive partners condoms are a significant impediment to experiencing it."
Given that condoms are the best behavioral intervention we have got, we need to be realistic about their use, which is often low among those who may be most in need of them. The three hackneyed imperatives, those to abstain, be faithful and use a condom, could all be trumped by one of the most basic and sometimes the most intense of human desires, the desire for sexual intimacy. Perhaps imperatives delivered without any authority whatsoever achieve the opposite to their intended result.
One day, it may be possible to supplement behavioral interventions with PrEP, microbicides and vaccines. But even then, it will be human behavior that determines whether this successfully prevents HIV transmission. As the iPrEx trial has shown, if people don't take the pills, they won't work. Unfortunately, the trial hasn't yet shown that if people do take the pills they do work. There's still a lot to learn about human behavior when it comes to HIV prevention interventions. The question is, will what we learn continue to be ignored?
By the way, it is not safe yet.
Monday, December 13, 2010
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