Sunday, October 17, 2010

Why Do UNAIDS Only Wish To Eliminate Some HIV Infections, And Not All?

Writing in the Huffington Post last month, Susan Smith Ellis paints a rosy picture for the future of prevention of HIV transmission from mothers to their children. Ellis's claim that this form of HIV transmission can be eliminated entirely by 2015 may well be true. But it is very unlikely that the goal will be achieved in high prevalence countries. And most of the 430,000 children a year, either born with HIV or becoming infected with it in their first few months of life, are from sub-Saharan African countries.

The HIV orthodoxy, led by UNAIDS, assumes that almost all HIV infection in African countries, around 90%, is a result of (unsafe) heterosexual sex. This assumption is not supported by evidence. Rather, mathematically modeled figures are used to support a set of prejudices that deny the possibility that non-sexual transmission occurs to any great extent in African countries.

It would be very foolish to claim that HIV is never sexually transmitted, or is hardly ever sexually transmitted. But it is no more foolish than claiming that HIV is never transmitted non-sexually. The virus is almost certainly transmitted both sexually and non-sexually. What is in question is the contribution that each mode of transmission makes to HIV epidemics in high prevalence countries.

There is evidence that sexual behavior differs greatly between high prevalence countries (or high prevalence regions in high prevalence countries), but the evidence is weak and doesn't stand up to scrutiny. In contrast, the evidence that health services in high HIV prevalence countries are poor, and could be responsible for some of the highest rates of HIV transmission, is more difficult to refute.

Rather than attempt to refute evidence that HIV may commonly be transmitted through unsafe healthcare, UNAIDS and others simply deny its existence. Occasionally, they refer to non-sexual transmission, either to stress how low it is in high prevalence countries or to warn UN employees to avoid using health facilities in high HIV prevalence countries. But their mantra is one of personal responsibility, of avoidable HIV transmission through unsafe sex.

If a woman is infected with HIV on or around the time of conception, her HIV status can be confirmed by a test some time round the end of the first trimester. If infection occurred before the time of conception, the test will confirm the woman's HIV status, but it won't confirm when infection took place. Yet the woman may not have been sexually active before the time of conception, or she may have taken precautions against both conception and infection. However, because she is pregnant, it will probably be assumed that she was infected sexually.

Perhaps it sounds reasonable to assume that the woman was infected sexually, but was her partner HIV positive? It is not routine in most health facilities to check. It can happen that the partner is tested but it very often doesn't. And given how much lower HIV rates are among men, there is a good chance that most HIV positive pregnant women were not infected by their partner (and it appears to be common for women to give birth to a child fathered by their partner). In fact, in Kenya, around 50% of married HIV positive women have a HIV negative partner.

Do we just assume that all these women also had sex with some HIV positive man, despite the fact that he was not their partner and despite the fact that most or all of them say they have only ever had sex with their partner? If we work for UNAIDS and many other organizations, that is pretty much what we assume. We assume that she is not only promiscuous, but that her word is not reliable. (There is also the mystery of how she became infected with HIV by someone who managed not to impregnate her. It's an awful lot easier to get pregnant than to be infected with HIV through unsafe sex.)

For many women, things are more complicated. They are infected in their second or even third trimester. They may be tested and found to be positive, which makes treatment, or at least precautions against mother to child transmission, more likely. But they may be infected so late in their pregnancy that their positive status is not detectable until after they deliver. In such cases, the need for treatment may not be discovered until it is too late, it may not even be discovered at all.

There are many other aspects to this area of HIV prevention but the aspect I wish to draw attention to is the assumption that most HIV transmission is sexual. Where this assumption is made, other modes of transmission are ignored. Pregnant women and babies receive a lot of medical procedures that men do not receive. One would hope that these medical procedures are safe and hygienic, that they do not pose any risk of infecting either the mother or the child.

But there is no such guarantee in many countries. Conditions in health facilities may be better than conditions in people's homes, but where conditions have been evaluated, they can be very poor indeed. Hospitals often lack personnel with the requisite training, equipment, hygiene procedures and other things that eliminate or reduce the risks of transmission of HIV or other blood borne diseases. Conditions at home are less likely to include the risk of infection with a serious virus, such as hepatitis or HIV. But equipment that is contaminated with these viruses could be common in health facilities. After all, sick people tend to go to hospitals if they can.

We don't need to assume that HIV is almost always transmitted sexually. Sexual behavior, indeed, should be irrelevant to health facility safety. Even mothers who are, or whose partners are, 'promiscuous' or engage in 'unsafe' sex, is not really the issue. The issue is whether the health care they receive is likely to expose mothers and babies to the risk of nosocomial HIV transmission, transmission through unsafe medical procedures. What countries with high HIV prevalence need is greater vigilance in health facilities and an admission that blood-borne infections can occur, just like they can, and often do, in rich countries.

And that's why Susan Smith Ellis is wrong in claiming that, because mother to child transmission of HIV could be eliminated, that it will be eliminated. As long as the assumption is made that the risk is almost all sexual and hardly ever non-sexual, and especially health care related, mothers and their babies will continue to be exposed to risks; many will be infected. Probably the biggest demographic group in high prevalence countries, sexually active women who are having children, are currently facing an avoidable risk, a risk that UNAIDS insists does not exist.


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