Thursday, January 20, 2011

Pregnant African Women Face Both Sexual and Non-Sexual HIV Risks

Researchers in South Africa aiming to estimate how many pregnant women were in the 'acute' phase of HIV infection, where their status would be undetectable using ordinary HIV tests, found that an astonishing 38% of women were HIV positive. They estimate the yearly rate of infection at over 11%.

It doesn't take a genius to work out that at these rates, the majority of women will be infected or dead from AIDS by the time they are in their thirties. These rates may have been found elsewhere, but they are still shocking. And yet, these researchers seem to think that they will achieve something by testing more and more people with better and better testing methods.

How are they being infected? The article assumes that most transmission is through heterosexual sex but this is just not credible. Some of the women were very young, they would hardly have had enough time to have enough sexual experience to become infected with a virus that is difficult to transmit through penile-vaginal sex.

If they are being infected by HIV positive men, who are these men? Incidence among men of similar age is often ten or more times lower. While it is argued that young women have sex with older men, who are more likely to be infected, are there even enough older HIV positive men to explain incidence figures among women? And are these women having sex with them? These have never been demonstrated.

Earlier research in South Africa has suggested that the probability of transmission is often 1, that a woman can become infected despite having only one partner and possibly even only having unprotected sex once. Would the researchers like to claim that there is a different strain of HIV in South Africa? Has the possibility of such transmission rates through heterosexual intercourse ever been demonstrated?

I don't believe so. I believe a lot of things are assumed, despite evidence to the contrary. And the authors of this paper go on making those assumptions. But HIV transmission will not be prevented if we don't even know how it is occurring. Rather than establishing how they may have become infected, it is assumed that most African women were infected sexually and conveniently forgotten that the chances of this happening to a few women, let alone to many, are extremely low.

Non-sexual HIV transmission must be considered. Most women, African and non-African, even young women, do not take stupid risks when they are pregnant. Most women don't take stupid risks even when they are not pregnant. Many HIV infections among pregnant women occur once they are already pregnant, often long into their pregnancy.

Transmission rates may well be higher among pregnant women, but so is the number of risks they face from being infected through unsafe injections or other medical procedures. And interestingly, the percentage of women in South Africa who visit an ante-natal clinic several times during their pregnancy is in the 90s. Compare that to a country like Tanzania, where some may visit once but the majority never visit at all, and where rates of transmission are many times lower than in South Africa.

Is it just a coincidence that HIV rates are often lower in areas where people don't have access to health services? Perhaps it is. But it is vital to find out if it is a coincidence. If it isn't a coincidence, then health services could be busy spreading the very virus they are supposed to be preventing.


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