Friday, June 18, 2010

There's Plenty of Evidence, Now We Need Investigations

Having looked at some of the figures for HIV prevalence in Kenya collected in 2007 and published earlier this year, I was not expecting another set of figures to come out so soon. But the 2008-09 Demographic and Health Survey (DHS) was released recently, so it's worth looking at some of these figures.

Since the 2003 DHS, prevalence has fallen slightly, from 6.7% to 6.3%. The major falls were in Nairobi and Coast provinces, though prevalence also fell in five other provinces. The only province that saw an increase was Western province, which went from 4.9% to 6.6%. This is good news, given that the 2008 Kenya Aids Indicator Survey (figures collected in 2007) found that prevalence had increased overall.

HIV prevalence in Kenya has always been higher in urban than in rural areas. However, the trend is for the share of infections in rural areas to increase. And as the vast majority of Kenyans live in rural areas, the number of people living with HIV in rural areas has long been higher than the number in urban areas.

The ratio of female to male infections overall has remained steady, at about 2 females for every one male. But in most provinces, this ratio has altered considerably. In Eastern province, for example, the ratio went from 4 women to every one man in 2003 to 4 women to every 3 men in 2008.

Despite the epidemic affecting women far more than men, there is still a lot of emphasis on the presumed effectiveness of male circumcision. This is said to give men some protection from HIV, though little or none to women. However, the mass male circumcision campaign in Kenya concentrates on only one of the three tribes in only one of the eight provinces, the Luo tribe of Nyanza. This makes the finding that "Luo men who are circumcised have roughly the same HIV prevalence as Luo men who are uncircumcised (16 percent compared with 17 percent)" rather shocking.

A campaign by CDC (US Center for Disease Control) aims to circumcise in excess of one million Luo men in the next year or so. I wonder how much they have told the men about this sort of finding.

The assumption that HIV is almost entirely transmitted sexually, especially by 'high risk' sex, is as pervasive as ever. That assumption is challenged by some of the findings, without being modified in any noticeable way. For example, in Table 14.7, relating to HIV prevalence by sexual behaviour, females reporting no sexual intercourse in the last 12 months have higher prevalence than those reporting 'higher risk' intercourse.

HIV prevalence was twice as high in females who reported sometimes using a condom (16%) than in those who reported never using a condom (7.8%). It's hard to know what is going on here but one thing is sure: if condoms were so ineffective in Western countries, there would be a thorough investigation. How can people be more likely to be infected if they use condoms? The Catholic and other Christian Churches should be happy as they have long preached against the effectiveness and morality of condoms. But if there is a question mark over both circumcision and condom use, how does Kenya now propose to reduce HIV infections?

It is hard to maintain the assumption that HIV is mainly transmitted sexually in Kenya without at the same time assuming that women must be far more promiscuous than men. There is no independent evidence showing that African women are more promiscuous than African men or that Africans are more promiscuous than non-Africans, for that matter. But over and over again in these figures women and girls, from a young age, are infected in much higher numbers than men. Assuming that these women are infected by men, where are all these men? Unless there is a small number of men who do most of the infecting and most of these women are having sex with them at some time, the HIV epidemic in Kenya is hard to understand.

There are figures that may support the contention that HIV is mainly transmitted sexually. For example, in both men and women, those with a history of having a sexually transmitted infection (STI), or symptoms of one, are twice as likely to be HIV positive as those who have not. But this could also suggest that people attending STI clinics are being infected with HIV through unsafe medical practices.

Indeed, the possibility of unsafe injections as a mode of HIV transmission is mentioned twice in this 455 page report. The fact that some people who are HIV positive reported never having had sex raises this possibility. But it is tempered by the possibility that sexual experience can be underreported, which it can. It can also be overreported. But will this lead to an investigation into why some people who say they have never had sex turn out to be HIV positive? I can't imagine such a finding not being investigated in a Western country.

If there are people who have been infected non-sexually in Kenya, and it's highly unlikely that there are none, this needs to be investigated. Because people who are sexually active can also be infected non-sexually. There has not been a proper investigation in Kenya into what proportion of HIV is transmitted non-sexually. The assumption that HIV is predominantly transmitted sexually has shaped HIV intervention policy and this policy appears to be failing. HIV prevalence has stayed at about the same level ever since the high death rates of the early 2000s have gone down.

Another area for enquiry is the large number of men who are infected whose partners are not and the large number of women who are infected whose partners are not. We can't just assume that they have all been infected because they are promiscuous, especially when they say they are not. Even where both male and female partners are infected it can turn out that they didn't infect each other. People are being infected with HIV and they have no idea why. The authors of the DHS have no idea why, either. HIV transmission will not be eliminated or even reduced substantially until we understand exactly how people are being infected.

There is no shortage of evidence showing that the behavioural paradigm is wrong; we cannot explain high rates of HIV prevalence in Kenya and other African countries on the basis of higher rates of 'risky' sexual behaviour. Research has shown that, on the contrary, high rates of the sort of sexual behaviour thought to be most risky are more likely to be found in Western countries, where HIV prevalence is low. If HIV is not only transmitted sexually, we need to establish how else it is being transmitted, to what extent and how best to eliminate these modes of transmission.


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