Drug-Based HIV 'Prevention' Strategies Alone Will Fail

While about 25% of HIV postive people in the US and the UK are thought not to know their status, only about the same percentage of people in some African countries are aware of their status. Many years of testing campaigns are only changing that figure slowly. But the pace of development in pharmaceutical products and treatment practices available is way ahead of the testing campaigns. Marketing and media campaigns are similarly ahead of the game, ahead of the evidence, some might say.

PrEP has been undergoing various trials for quite a few years now, but it has not yet shown itself to be the most appropriate strategy in countries with high HIV prevalence rates. Even 'test and treat' ("testing all adolescents and adults annually for HIV infection and immediately treating those found to be infected") may sound good on paper; but it will struggle to prove itself as a strategy in less well off countries.

Test and treat would work best if it could catch new HIV infections at the earliest clinical stage, during which it is most likely to be transmitted to others. But if far less than half of the HIV positive people know their status, the chances of a substantial number of early infections being identified are small. It is more likely that most infections will continue to be identified when people have been infected for many years, even at the latest stage of infection (which is often far too late).

If the plan is to test sexually active people every year, this will involve a huge scaling up of current testing practices and a massive change in the testing behaviors of the entire population of quite a number of poor countries. One might even ask if testing sexually active people once a year is enough, given that 'early stage of HIV infection' means the first six months. (Testing at least every six months is estimated to be required by the author of the above article.) But this must be compared to the consideration that the majority of people in African countries have never tested; many of those who have tested only did so once.

Like PrEP, test and treat seems suspiciously passive, as if we are waiting till lots more people become infected and then treating them with the ostensible aim of preventing further infection. In conjunction, these strategies will be great for pharmaceutical company profits, there's no question about that. But as to whether they will cut infection rates substantially, there is plenty of room for doubt. Early initiation of antiretroviral therapy (ART) has also been pushed as a highly beneficial strategy, but the evidence is not yet convincing.

These three strategies (PrEP, test and treat and early ART initiation) are a little like prevention of mother to child transmission (PMTCT) in that they require at least one infection in order to 'protect' some unknown number of infections in the future. The percentage reduction in mother to child transmission gained through use of PMTCT is, of course, well established. But brilliant levels of PMTCT rollout, and it is by no means widespread in many of the highest prevalence countries, is puny when compared to low HIV prevalence among young women, pregnant women and mothers.

South Africa has the highest number of HIV positive people in the world, over five million. The majority of new infections are occurring in young women. To the best of my knowledge, no large scale effort has ever been made to asses the sexual and non-sexual HIV risks that these women face. The view that they are almost all infected through heterosexual behavior is still just an assumption, albeit one supported by almost every HIV academic currently writing. If there are HIV positive people infecting these women, find them. They also need treatment, more urgently than anyone else.

This is not a call to increase the levels of anti-African prejudice that UNAIDS and the HIV industry currently enjoys; it is a serious suggestion that sexual partners of young HIV positive women be identified. Many South African men, young and old, will be found to be HIV negative. The same would be true of men in other high prevalence African countries. Therefore, young women's non-sexual risks also need to be identified.

The above HIV drug-based strategies center around the belief that HIV is almost always transmitted through heterosexual sex and almost never through any non-sexual routes, such as unsafe medical or cosmetic services. If these assumptions turn out to be false, the above strategies will cease to appear so tempting.