The view that HIV is almost always transmitted through heterosexual sex in high and medium prevalence countries in Africa is disturbing because it is assumed to be a true and accurate starting point for most research. If research began without the assumption and then adopted it once it was shown to be useful and/or not inimical to shedding light on HIV transmission, that wouldn't be so bad. But surely, making unwarranted assumptions is something to be avoided by serious researchers?
Some researchers in Uganda analysed various HIV subtypes found in a group of women engaged in 'high-risk' sexual behavior to find patterns that might show how the women were infected. But the assumption was that the virus was transmitted sexually, hence the use of women considered to face high levels of sexual risk ("sex workers and bar workers").
However, many of those who face high levels of sexual risk can also face high levels of non-sexual risk. Many sex workers regularly attend sexually transmitted disease clinics for the treatment and prevention of STIs, to receive injectable hormonal contraceptives and undergo various kinds of testing that can be invasive. In countries where health services are not always well staffed, well equipped or well run, the possibility that instruments can be contaminated is always present.
In fact, the researchers found that 75% of participants had either subtype A or D, which doesn't suggest a huge amount of variation. If most people were being infected sexually by a virus that had been going around for several decades, one might expect a lot more variation. Perhaps this suggests that most people are being infected by a small number of different sources, which might more likely be a clinic or group of clinics?
Or perhaps not. But the research only showed that there was some clustering of subtypes around particular geographical areas. Showing that several people may have closely related viruses does not necessarily mean they all belong to the same sexual network. It could also mean they all attend the same STI clinic or the same hospital. But the most disturbing thing about the research, then, is that no attempt was made to identify any non-sexual risks that participants may have faced.
The researchers are effectively emasculating any possible value their research might have. All they have shown is that some people have HIV virus subtypes that may have come from the same source. This sheds no light on what that source was. The fact that all the participants engage in 'high risk' sexual behavior may be relevant, but we have no idea of how relevant.
Since early on in the HIV epidemic in African countries, the same groups have been rounded up for research that has similarly failed to examine the non sexual risks they may face. Fingers have been pointed at sex workers, long distance drivers, fishermen, people living in border towns, etc. But most, if not all of them, also face non sexual risks. HIV does tend to cluster round main roads and in densely populated areas. But it also tends to cluster around health facilities.
Another group of researchers have questioned the work carried out in Uganda for these reasons. They suggest that the work is not finished until all the risks the participants face have been assessed, not just the sexual risks. Others who may have been involved in transmitting or being infected with HIV need to be contacted and their virus subtype also needs to be identified. This will allow a proper infection network to be drawn up, not just a sexual network.
But what are the chances of people who seem obsessed with the sexual behavior of Africans carrying out research into the possibility that HIV is not always sexually transmitted? If you are faced with a massive epidemic that you assume was spread sexually, you will then make similarly unfounded and ridiculous assumptions about the sexual behavior of those infected. And if you are like these researchers in Uganda, you may forget to reflect on the sheer racism of attributing such absurd levels of sexual behavior to fellow human beings.