Saturday, October 29, 2011

Investigating Non-Sexual Risk is the Key to Reducing HIV Transmission and Stigma

In a paper published in 2006, Drs David Gisselquist and Mariette Correa identified five models that purport to demonstrate that the HIV epidemic in India is driven mainly by heterosexual sex between commercial sex workers, their clients and their clients' partners. However, when the authors applied the available empirical data, they found that such heterosexual drivers could only account for a fairly small percentage of transmission.

The models they looked at used exaggerated estimates of the numbers of sex workers, the number of clients, the number of contacts between sex workers and their clients, the percentage of contacts that were unprotected and the number of sex workers and clients who were HIV positive. They also used a very high transmission efficiency figure, which is not borne out by empirical research.

Even using some of the very high figures available, Gisselquist and Correa were not able to account for the estimated number of HIV positive people in India. The claim that almost all HIV is transmitted through heterosexual sex, mainly as a result of commercial sex work, appears to be unfounded. And although estimates of HIV prevalence in India have since been radically revised downwards, it is still vital to identify the main drivers of the epidemic in order to reduce transmission

About 6 years earlier, shocking HIV and sexually transmitted infection (STI) rates were found among 'bar workers' in Tanzania. HIV prevalence was 68%, syphilis was 8%, chlamydia was 12%, gonorrhea was 22%, etc. The fact that both HIV and STI rates were high might be taken to support the assumption that HIV is almost always sexually transmitted. But the article concluded that "few sociodemographic and behavioural variables correlated with STI risk".

As is customary in African countries when collecting self-reported sexual behavior data that doesn't match the expectations of the researchers, the information is considered to be unreliable. Perhaps like the models mentioned above, some figures are overestimates and some are underestimates. But, whereas the unreliable data that conforms to the researchers expectations is used to support policy decisions, data from Africans that is said to be unreliable is ignored or scaled up or down, as required to match the expectations.

In the very different scenarios in India and Tanzania, we end up without an understanding of how HIV is being transmitted and, therefore, what kind of interventions would be most appropriate to reduce transmission, perhaps even eliminate it entirely. Otherwise, we get reports of 'successful' work in the field which is unlikely to have had any real impact, because it fails to address all the drivers of the epidemic.

In the Tanzanian case, not all of the women were sex workers. 58% of them "reported having had one or more casual partners during the past 12 months and approximately 45% reported having received money for sexual favours". But despite the relatively low level of risk, for 68% to become infected, virtually all of them must have been exposed to HIV, perhaps several times. So what kind of exposures did they face? HIV prevalence among men is far lower than it is among women in most parts of Tanzania.

Currently, national HIV prevalence in Tanzania is roughly the same as that among sex workers in India, about 6%. Sex workers in India and ordinarly adults in Tanzania do not face high enough levels of sexual risk to explain high rates of sexual transmission. And only imaginary levels of 'unsafe' sexual behavior and sexual transmission probability could result in 68% of any population being infected through heterosexual sex.

In desperation, the authors suggest that "male clients of female bar workers may function as a bridging group for HIV transmission in the general population". (Notice how these bar workers are assumed to be sex workers, despite evidence to the contrary.) But this kind of model of transmission does not work when trying to explain a generalized epidemic, as Gisselquist and Correa have shown. It only explains a small percentage of transmission. What other risks do people face, not just sex workers?

Smug, self-administered pats on the back, like the one the Gates Foundation gives itself for work with sex workers in India, does not explain how HIV is being transmitted. Rather, it ignores the fact that HIV is being transmitted non-sexually, perhaps through unsafe healthcare and cosmetic practices, as well as sexually. The clear need for an investigation into the roles of various non-sexual routes of HIV transmission has long been demonstrated, over and over again.

How many more years will it take before researchers are willing to divert some of their attention from sexual behavior and look carefully at the non-sexual risks that people in developing countries face? Stigma doesn't arise because of lack of understanding about HIV transmission, it arises because the HIV industry insists that 80-90% of the virus is transmitted sexually. The key to reducing HIV transmission and HIV related stigma is one and the same: investigating the relative contribution of various forms of non-sexual risk.

[For more about non-sexual HIV risk from unsafe healthcare and cosmetic practices, see the Don't Get Stuck With HIV site.]


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