Sunday, July 24, 2011

Data Trumped by Idle Speculation and Pig-Headedness, as Usual

For many years, UNAIDS and the rest of the HIV industry have been sending out the message that everyone is at risk of being infected with HIV. However, it has never been true that everyone is at risk and there was never any reason for claiming this. The fact that HIV tended to cluster in urban areas, among wealthier, more mobile and better educated populations has been clear for a long time.

One of the latest papers to include detailed spacial data which demonstrates this clustering effect is entitled 'Localized spatial clustering of HIV infections in a widely disseminated rural South African epidemic', by Frank Tanser and colleagues. The data they produce is very interesting, but the same can certainly not be said of the conclusions they draw.

Unsurprisingly, they assume throughout that HIV is almost always transmitted through heterosexual sex in African countries, the so called 'behavioral paradigm'. And the study is in South Africa, the country with the largest number of people living with HIV in the world. As usual, the assumption is unexamined and unsupported in any way.

The study finds that high HIV prevalence clusters close to the National Road and that it is far lower in inaccessible rural areas. 40% of infected people live within 1km of the National Road. Also the "estimated density of HIV-infected individuals (total HIV cases per square kilometre) living within 1km of the road is 15.7 times higher than the mean density of infected individuals across the remainder of the study area."

Those infected are also better educated, wealthier and far more likely to be employed. No surprises there. And they are also less likely to be migrants. Migrants, especially internal migrants, are one of the groups often said to be at high risk of being infected and of infecting others. But the HIV industry has always been bad at identifying risk groups or, I should say, good at ignoring any evidence that may help identify them.

Whatever theories the paper's authors may have, indeed, whatever prejudices, all this data supports the view that HIV is not entirely spread sexually. The populations in this and other studies also have something else in common: they all live close to or have easy access to health facilities. Wealthy, well educated, mobile people with jobs tend to go to health facilities.

On the other hand, rural people tend to go to health facilities far less often, for various reasons, including poverty, lack of mobility, lack of health related education and the sheer lack of decent, affordable, accessible health facilities. Do these features of serious underdevelopment give people protection from HIV infection? Well, that's a hard question to answer if researchers like Tanser and colleagues don't even raise it.

The authors speculate about why the factors that may have been significant in HIV transmission during an early phase of the epidemic appear to be significant still and why this apparently heterosexually transmitted virus has not been more evenly spread among the population. Just how many warning signs do they need that their overall hypothesis about the virus being spread almost entirely through heterosexual sex is wrong and is little more than an anti-African prejudice?

As if things are not bad enough, this sort of idle speculation and pig-headed refusal to consider some fairly obvious alternatives to the behavioral paradigm is going to encourage those baying for 'treatment as prevention' and pre-exposure prophylaxis (essentially, means of substantially increasing the tonnage of drugs being thrown at the epidemic) to be rolled out in high prevalence countries.


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