Treatment as Prevention: The New AIDS Panacea?
By Fiorenzo Conte
There is ensuing debate between those who advocate more funding for Antiretroviral Treatment (ARV) to offer treatment for HIV positive people and those who argue for more funding towards prevention to counter the epidemic. The results of a new study say that this is a false dichotomy: the drugs which suppress the HIV level of an HIV infected person will zero the odds of the person passing the virus on. In other words, you can get treatment and prevention in the same pill. The potential consequences of such a discovery are enormous. As the Economist points out, if you can get enough people on treatment, it would be like vaccinating them, as the chain of transmission gets interrupted. This would imply getting all the 34 million people infected on treatment and such effort would cost a lot of money (roughly doubling what is currently spent every year on the epidemic i.e. $16 billion). However, according to The Lancet the money spent on improved access to treatment and screening needs to be weighed against the money that is saved by not treating those who would have been infected without such intervention. And if you compare money spent vs. money saved, the balance will be positive. If these arguments hold, it follows that if you can get enough funding and if you tilt this money towards treatment you can realistically hope to end AIDS. This is the positive part of the story. There is however another part of the story, which reveals that ARV treatment is not an easy fix to end AIDS and that more money alone could not be sufficient. So let’s have a look at why some of the assumptions of the argument above could be problematic.
1. Get enough people on drugs and it would be like vaccinating them. There is something very similar to this in the fight against malaria: long-lasting insecticide nets. If you get enough people sleeping under the net ( roughly 80% coverage) you can break the chain of transmission. However, there is a problem: such high coverage has never been achieved in any place. This is because it is difficult to get the nets to the people that need them, it is more difficult to ensure a long term supply and it is similarly hard to convince people to use them. There are several problems with getting people on ARV. People do not get tested because they are fearful of knowing their status, hence they remained undetected. People who are HIV positive are not compliant with the treatment because they fear being stigmatized if seen in facilities offering HIV treatment. In other words, any method whose effectiveness hinges upon an extremely high uptake and long-term usage (in the case of ARV all the people positive, even those without symptoms, should follow the treatment) is really complicated when it comes to being rolled out on a large scale.
2. Most of the extra spending (for ARV treatment) would be offset by savings on the treatment of those who would have been infected, but were not. This claim assumes that if all HIV positive people are put on drugs, the rates of infections are bound to decrease. There could be however some unintended consequences. By making ARV drugs largely available you turn AIDS into a chronic disease: you cannot cure it, but you can have a normal life. If not qualified, this message can be perceived by people as a green light for risky sexual behavior. This is called ART-related risk compensation and it means that people increase risky behavior now that ART are largely available. Research in Mozambique and Kenya show that a wide availability of ART can in fact be associated with increased risky behaviors and infections.
The fact that people who are on treatment will not pass on the virus adds another weapon in the fight against HIV/AIDS. However, given that getting a lot of people on treatment is not easy and that people could increase their risky sexual behavior, directing all the money towards treatment may not be wise. Screening, use of condoms, and effective prevention messages remain necessary measures to counter the epidemic.