Wednesday, July 7, 2010

Don't Just Repeat the Mantra; Follow it!

One of the people who came up with the idea of a 'no sex month' to reduce HIV transmission by 10-45% (for that month) has published a paper which finds that neither poverty nor wealth drive the HIV epidemic. The no sex month idea suffers from what could be a major flaw: it will only reduce sexually transmitted HIV infection. That may sound obvious but this researcher assumes that most, perhaps even all HIV, is transmitted sexually. So his analysis of the finding that neither poverty nor wealth drive HIV is similarly flawed.

This latest paper may be more comprehensive than previous ones. But the suggestion that wealthy people are often more likely to be HIV positive than poorer people has been made a number of times over quite a few years. It has also been noted that higher levels of education can be correlated with higher rates of HIV. And it has been clear that these trends can change, with the correlation becoming less pronounced and even reversing over time. Whereas earlier in an epidemic, wealth and education may correlate with higher HIV rates, they may correlate with lower rates later on.

It has been clear also that HIV rates differ strongly among men and women, with prevalence among women being far higher than that among men at later stages in epidemics. Correlations between wealth and education are often stronger for women and less pronounced for men. And correlations can be stronger in poorer countries than in wealthier countries. So far, so good, these findings are all interesting and revealing. Before they were established, many pronouncements were made about connections between HIV and poverty and HIV and education which resulted in ineffective strategies.

But the paper's author links all these findings to the unspoken assumption that HIV is mostly transmitted through heterosexual intercourse, that the 'behavioral paradigm' is true. The extent to which HIV is transmitted sexually is not clear because the extent to which it could be transmitted non-sexually has never been properly investigated.

Many poor African countries have high HIV rates. But many richer African countries have even higher rates. Even within Kenya, the highest HIV rates are not found in the poorest areas. North Eastern province is by far the poorest province, with the worst education indicators, yet HIV prevalence is very low. Higher rates are found in Nairobi, whose population is richer and better educated, on the whole. But no matter how you slice up the population, high HIV prevalence does not correlate with wealth, poverty, inequality, education or anything else that is obvious.

If you assume that HIV is mostly transmitted sexually, you wonder why infections among women can be four times as high as those among men. Just who is infecting these women and under what circumstances? You could assuage these doubts somewhat by pointing out that women are more susceptible, for various different reasons. But then you find the richest women with the highest levels of education in Tanzania are far more likely to be infected than the poorest. This changes over time, but the trend certainly doesn't reverse. And the pattern among men is completely different. With the behavioral paradigm, you have to tie yourself in knots to understand just what sort of sexual behavior is going on here.

It helps if you are quite racist, which is lucky for UNAIDS because as an institution, they are racist through and through. It also doesn't do any harm to be sexist and UNAIDS also ticks that box. You then make up various different (and fairly improbable) hypothetical scenarios and you come up with this:

Poor people in some settings undertake particular risky practices – e.g. earlier sexual debut or reliance on transactional sex – whereas wealthy individuals may engage in other risky practices, such as participation in broader social and sexual networks or sex with higher numbers of (voluntary) regular partners.

It doesn't mean very much but it sounds good, especially as there are some citations in the original article, giving the whole thing a veneer of authenticity. But there is no evidence that Africans, rich or poor, male or female, engage in large enough amounts of the sorts of behavior considered risky enough to explain the devastating epidemics found in Sub-Saharan African countries. Sexual behavior varies from place to place, but not in the way UNAIDS and the author in question would like. Most Africans do not have lots of risky sex, only some do. But some Europeans do, as do some Americans. You just don't find HIV epidemics in Europe and America like the ones in Africa.

The author goes on :

Effective action requires unpacking the black box of behaviour by recognizing that HIV infection in poorer groups may arise from certain lifestyles and risky behaviours related to poverty, whereas HIV infection in wealthy groups may be due to different lifestyles and risky behaviours related to their wealth.

This may all be true but it is only true of sexually transmitted HIV.

If you don't assume the truth of the behavioral paradigm and you accept that some HIV is transmitted non-sexually, they you can consider less improbable and more testable scenarios. For example, you could look at the different behaviors of males and females relating to health care. Women could be exposed to more of the kinds of medical procedures and cosmetic procedures that might carry a risk of HIV infection. Richer women could be exposed to more of these procedures than poor women. Earlier on in the epidemic, education and wealth may have had little influence on women's attitudes towards health and cosmetic treatments but this could have changed as more became known about the epidemic.

If it is assumed that all or most HIV is transmitted sexually then you will end up with HIV prevention programs that aim to change people's sexual behavior. That's what we have ended up with, even worse, most of the programs don't work. Unless we also target non-sexual transmission, which means establishing its contribution to the HIV pandemic first, we will never 'know our epidemic', in the words of UNAIDS. And if we don't know our epidemic we will never 'know our response', either. The key to a mantra is not just to repeat it, you also have to follow it.


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