Saturday, February 5, 2011

Why is HIV Prevalence Higher Close to Health Facilities?

Caryl Feldacker, Susan Ennett and Ilene Speizer have published an article entitled "It's not just who you are but where you live: an exploration of community influences on individual HIV status in rural Malawi". Differences between urban and rural HIV rates have always been striking and have often seemed counterintuitive.

For example, people in rural areas often have less access to health facilities due to distance, cost and poor infrastructure. Yet HIV rates are almost always noticeably higher in urban areas, where infrastructure is better, there are more health facilities and people are wealthier.

This has been seen as an anomaly because poverty and accessible health services are usually associated with better health. Yet, the phenomenon is common. In Kenya, the province with least access to health, North Eastern, has by far the lowest HIV prevalence.

North Eastern also has other conditions which are sometimes associated with high HIV rates, such as low age of sexual debut, especially for females, high rates of female genital mutilation, high rates of intergenerational marriage (where the man is significantly older than the woman), low rates of condom use and high birth rates.

Several years ago, it was noted that HIV rates decline as you move from roads and urban areas in Tanzania, although the virus was becoming more common in rural areas and declining slowly in urban areas. So similar findings in Malawi are hardly a bolt from the blue.

But these researchers find that the closer you are to a health facility, the more likely you are to be infected. Those further away are less likely to be infected. In addition to highlighting the significance of non-individual possible factors in the transmission of HIV, they find that individual behavior is not nearly as significant as UNAIDS and the HIV industry insist.

Alas, what the researchers find, they try to explain away. They cite David Gisselquist and others who suggest that proximity to health facilities may increase the risk of HIV transmission because of unsafe medical practices. But the researchers speculate that a more plausible explanation is that proximity to health facilities happens to correlate with areas where risky sexual behavior is more common.

They claim this sexual behavior explanation is more 'plausible'. Well, it is if you accept that HIV transmission is almost all explained by reference to sexual behavior. These researchers show clear signs of being bitten by their own behavioral paradigm. They were not expecting to find such a clear indication that health facilities might actually be part of the problem.

So they deny it. Rather than accepting Gisselquist and co's explanation, which is compatible with their own somewhat futile specualations, they simply reject anything that threatens the paradigm. They have gone so far and no further. It's such a pity to see good research being used to prop up a crumbling theory, especially given the influence of that theory on global HIV policy.

One of the things the researchers say is particularly hard to fathom. They hypothesize "those with greater access to roads and cities, will be more likely to engage in HIV risk behaviors, and therefore, more likely to be HIV infected. Persons with greater access to health facilities will be less likely to engage in HIV risk behaviors and, therefore, less likely to be infected with HIV."

The first part of the claim has been one of the biggest failures of orthodox HIV transmission theory. There is no evidence that levels of risky sexual behavior are higher where HIV rates are higher. And there is no evidence that levels of risky sexual behavior are higher in high HIV prevalence African countries than low prevalence African and non-African countries.

And why would people with access to health facilities be less likely to engage in risky sex? Their rejection of Gisselquist and Co's theory even requires that they reject this hypothesis.

In fact, those who have greater access to roads and cities are, more or less, the same people who have greater access to health facilities. But there is nothing about health facilities themselves that results in lower levels of risky behavior (or higher levels, for that matter). There may be a bit of wishful thinking involved here, but otherwise it's a strange hypothesis.

It remains to be seen whether other researchers accept Feldaker and Co's analysis, which has the sole advantage of not threatening the mainstream. But others may begin to wonder if the possibility of non-sexual transmission, health care related transmission in particular, should be reconsidered in the light of this and other evidence. HIV prevalence may be higher close to health facilities for all sorts of reasons, but it's time to find out if health facilities are transmitting more HIV than UNAIDS has been telling us.

[Read about pre-exposure prophylaxis (PrEP) and health priorities on my other blog.]


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