Friday, May 6, 2011

High HIV Risk, Low Prevalence, Is Pakistan a Miracle?

According to a situation analysis of HIV in Pakistan, the country is "at high risk of HIV infection" but that presently prevalence is very low. In fact, prevalence is under .1%, which is significantly lower than in the US (estimated at .6%). Only a few thousands of HIV positive people have actually been identified.

Pakistan's epidemic is considered to be 'concentrated', that is, the majority of infections are among members of high risk groups, such as intravenous drug users and men who have sex with men. It has been suggested that the epidemic is 'in transition', but prevalence might just as easily be lower than the estimates would suggest.

There are references to "indiscriminate transfusion of unscreened blood" and "unsafe injecting practices in formal and informal healthcare settings". If these are true, then HIV can not be truly said to have penetrated the country's health services. Those types of transmission would spread the virus very quickly.

Despite the lack of conclusive evidence, it is also estimated that over 50% of HIV transmissions are through heterosexual sex. This could be compared to the 80% (sometimes 90%) estimated by UNAIDS for heterosexual transmission in African countries. The two estimates should certainly be treated with equal skepticism.

It might also be wondered how Pakistan could report indiscriminate transfusion of unscreened blood and high levels of unsafe injecting when these modes of transmission are said to be almost non-existent in African countries. Are Africa's health services so much more advanced than those available in Pakistan? And if they are, why are UN employees warned not to use them? Why do rich Africans opt for medical care in Western countries?

Transmission rates in Pakistan attributed to intravenous drug use and male to male sex are comparable to those found in African countries. But in Pakistan, 27% of transmissions are said to be due to undetermined origin. In African countries, none are so attributed. Epidemiologists much be far more efficient in African countries.

So, aside from having very low prevalence in Pakistan, another stark difference is that in Africa, far more women are infected than men. In Pakistan, it's the other way around, where "86.8 % of reported HIV positive cases are found to be men". Given that probability of transmission from women to men is said to be about half that from men to women, the contribution of heterosexual transmission should be relatively low, certainly lower than 50%.

The differences found in HIV epidemics in Pakistan and, say, South Africa (prevalence 18.1, ie, 181 times higher), are enormous. So enormous that you might ask if it is the same virus that is being referred to as 'HIV' in both countries. My suspicion is that it is the same virus, but we are being lied to about the respective contribution of non-sexual transmission in African countries. Which may be good news for Pakistan, but not for African countries.


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