Friday, April 15, 2011

Circumcision Enthusiasts: Screw the Evidence, We're Going Ahead

HIV prevalence has been high in Kisumu since early on in Kenya's epidemic. Rates went higher there than anywhere else in the country and they are still about twice as high as the next highest area, and three times as high as the national figure. This meant that a lot of HIV research work has been done in Kisumu. But no explanation has ever been given of why rates should be so disproportionately high there.

Naturally, fingers were pointed at the fact that people in Kisumu must have a lot of unsafe sex. But what is it about Kisumu (or Luo) sex that makes it so different from sex in other parts of the country? Some people have more than one partner, a few have lots. Most don't use condoms very much and many have their first sexual experience when they are still teenagers.

But those things could all be said about most of the other tribes and cities and provinces of Kenya, and about some people in every country. Birth rates, a sure sign of unprotected sex, are highest in Northern, ethnic Somali inhabited areas. There isn't really anything extraordinary about Kisumu or Luo sex that anyone has been able to discover.

Also early on in the epidemic, it was pointed out that Luo men are not usually circumcised. It was suggested that this might make them more susceptible to HIV. Research has shown that HIV transmission can appear to be connected to circumcision status. However, though in some places circumcised men are less likely to be infected, in others uncircumcised men are less likely to be infected.

But this finding didn't make the people for whom mass male circumcision is their personal cursade very happy. The more research they did, the more ambiguous the effect of mass male circumcision appeared to be. But they are still at it. In fact, research suggests yet another thing that was recognised early on in the HIV pandemic: that HIV is probably not always transmitted sexually.

The risk factors are particularly interesting, not just because risky sex is likely to be driving a good deal of HIV transmission, but because some non-sexual risk factors are also likely to be involved. Both medical injections and traditional practices (saro, bloodletting) were implicated. Those who received injections in the last 6 months were three times more likely to be infected that those who had not and those who ever practiced bloodletting were twice as likely to be infected.

Another surprise was that men who reported washing their genitals immediately after sex were also less likely to be HIV positive. This gives some confirmation to the view that circumcision may not be necessary if men take measures to ensure penile hygiene. Little research has been done into this phenomenon but it is not clear why the authors of this research paper are still advocates of circumcision without knowing how and why HIV transmission appears to be correlated with circumcision status, sometimes positively correlated, sometimes negatively.

Catholics were more than twice as likely to be HIV positive as members of other religions and this was not related to condom use. In fact, condom use is not even a reliable indicator of risk.

The authors try to explain away the data about receiving injections by arguing "because this is a cross-sectional analysis, it is also possible that HIV positive men were more likely to report recent injections to treat HIV/AIDS related illnesses". But these are young men. Even the HIV positive among them are unlikely to be receiving injections related to their HIV status.

While 72% of eligible HIV negative people took part in the survey, only 22% of HIV positive people did so. This could skew the results considerably, though it's not possible to know in which direction they would be skewed. But despite this, and despite the indications that HIV is not always transmitted sexually (or 90%, as is usually claimed), the authors are still devoted advocates of mass male circumcision.


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