Sunday, October 3, 2010

Testing the HIV 'Test and Treat' Strategy

A 'Test and Treat' strategy, also referred to as 'Treatment as (or 'is') Prevention', has not shown very good results in a study in China. Such strategies were the most hyped item on the agenda just under two years ago in the HIV/AIDS world. The claim was that HIV positive people responding to treatment usually have a very low viral load so they are far less likely to transmit the virus to their sexual partners; therefore everyone in a population could be tested regularly, perhaps every year, and immediately put on antiretroviral (ARV) treatment if found to be positive.

The study in China looked at discordant couples, couples where only one partner is HIV positive. HIV transmission rates were relatively low, at 4.3% over a three year period (a seroconversation rate of 1.7 per 100 person years), though the rate increased over time.

Risk was higher where sexual activity was higher and where condoms were not always used. Risk was also higher among those who had lower scores in a psychological test. But the ARV treatment itself did not lower the risk of transmission.

Another piece of research could lend some corroboration to the Chinese research. Though not looking at Test and Treat specifically, it does suggests that such strategies may not be very effective outside of the very closely monitored trial conditions that applied to earlier randomized controlled trials.

This piece of research investigated the effects of $6 billion of PEPFAR funding (President's Emergency Plan For Aids Relief) on AIDS related deaths and prevalence in recipient countries. While the fund may have had some success in lowering death rates from AIDS, it did not significantly lower prevalence over its first four years in operation. The authors and speculate that four years may be too short a period.

It is estimated that death rates were reduced by 10.5% (an estimated 1.2 million deaths). However, the number of people put on treatment could be as much as 100 times higher than in the Chinese research. If mass treatment had much effect on transmission, one would expect some detectable effect on prevalence, even after just four years.

But unless you believe the UNAIDS orthodoxy about HIV being mainly transmitted sexually in African countries, the low rates of sexual transmission found in the Chinese research will not be very surprising. The area where the research took place, Zhumadian, has higher than average HIV prevalence because of the use of infected blood products from paid plasma donors in the 1990s.

Perhaps the investigators in the PEPFAR research should not have been so surprised that the $1.2 billion allocated to prevention, about one fifth of the total, had little impact. Because most PEPFAR prevention 'strategies' assume the truth of the UNAIDS orthodoxy, that most HIV transmission in African countries is sexual. Maybe they will now start to see that the orthodoxy needs to be challenged.

In addition to casting doubt on the completely untenable and highly racist assumptions that make up the orthodox view of HIV transmission in African countries, the above research could also question the medicalization of HIV and other diseases. This is the implicit assumption that health is just a matter of treating diseases with drugs, as opposed to ensuring that the conditions under which diseases spread are dealt with.

If high rates of non-sexual HIV transmission can occur in China, they can occur in African countries. And if low rates of sexual transmission can occur in China, they may also be occurring in Africa. Low rates of sexual transmission may be the norm in Africa and it is late in the day to start investigating the contribution that non-sexual transmission plays. But we have a duty to investigate this if we want to have any impact on African epidemics. We can no longer allow prejudices to determine what should and should not be asked about the massive rates of HIV transmission found in a handful of countries in Africa.


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