Pre-Exposure Prophylaxis or PrEP

Pre-exposure prophylaxis (PrEP) involves putting HIV negative people on antiretroviral drugs (ARV) with the aim of protecting them from HIV infection. This blog looks at some of the pros and cons of PrEP.

Monday, December 12, 2011

Treatment As Prevention: Dream or Nightmare?

In the light of current enthusiasm for 'treatment as prevention (or 'is' prevention or some other permutation)', it's sobering to read an article from the US entitled 'Only 28% of HIV patients have condition under control'. The idea of treatment as prevention, sometimes referred to as 'test and treat', is that it will be feasible to test about 80% of an entire population, not just once in a while, but regularly, perhaps once a year or more. Upon being found HIV positive people will receive immediate treatment, regardless of clinical stage.

The US spends over $7,000 per capita according to WHO estimates for 2009; that's over 15% of GDP. Tanzania, in contrast, spends $57 per capita, 4.5% of GDP. So if only 28% of HIV positive people in the US are rendered unlikely to transmit the virus to others through having a low viral load, at least through (safe heterosexual) sex, and about 20% of those infected don't even know they are positive, where does this leave countries like Tanzania?

Figures for how many Tanzanians are on antiretrovirals vary a lot and are vague; they don't make it clear what percentage on treatment have the virus under control. Quite a lot of people said to be on treatment are lost to follow-up every year. Many die or move to another area, but this also suggests that numbers on treatment are overestimated as some are registered in more than one place. The majority of HIV positive people in Tanzania are not on treatment and a majority of the population have never been tested for HIV. A large number of people who have never been tested are estimated to be HIV positive.

I just don't feel convinced that the money is going to be stumped up to test tens of millions, perhaps hundreds of millions of people every year for the foreseeable and to treat tens of millions for several decades to come. But perhaps I'm just a sceptic (or 'skeptic' if you're in the US).