Monday, January 17, 2011

HIV Policy Needs to Follow Health Policy, Not Vice Versa

Following my last post, I received a comment raising the issue of the role of sexually transmitted infections (STI) in HIV transmission. This is a vital issue so I gave a brief response but promised to answer more fully in a blog post.

Firstly, health is not just a matter of absence of disease, so health policies should aim to prevent diseases where possible, as well as treat them.

This has clearly not been done with STIs. Preventable and treatable STIs are endemic in many developing countries and, regardless of whether they play a role in HIV transmission, sexual health is in urgent need of prioritization.

Very high levels of STIs, and of all easily preventable or curable diseases, are a symptom of poor health services, services that have been declining for decades. Concentration on HIV has often meant that STIs and other diseases have been ignored, so this has added to the serious STI epidemics that have developed.

However, the role of STIs in HIV epidemics has not been clearly demonstrated and there have been conflicting reports, especially where tests with treating STIs as a HIV prevention intervention have been carried out.

There is an interesting article on this subject called "Confound it: latent lessons from the Mwanza trial of STD treatment to reduce HIV transmission", by David Gisselquist and John Potterat. This is about the STI treatment trial in Mwanza, Tanzania which, according to the researchers involved, showed that reducing STIs could reduce HIV transmission.

The researchers' claim is odd because STIs were not reduced much during the trial, yet HIV transmission did seem to be reduced. Also, similar trials were carried out in two other locations and neither of them demonstrated any benefits for STI treatment.

Gisselquist and Potterat have two suggestions as to why the trial results in Mwanza differed so much from the two in Uganda. For a start, those taking part in the Mwanza trial appear to have received safe health care, which is something most East Africans don't receive. And there happened to be an injection safety initiative taking place at the same time as the STI trial.

The authors warn that continuing to target STIs without also improving health services by making it far safer, especially in relation to injection practices, there is a risk that transmission of HIV and other blood borne viruses will increase.

In the mid 1980s in Nairobi, HIV rates were found to be over 80% among sex workers at a time when they were extremely low among males in the city. The hypothesis, still the dominant hypothesis about HIV transmission in African countries, was that these women were infected through sexual intercourse with HIV positive men.

But if few men were infected, that seems unlikely. To explain such high transmission rates among women, even though they were engaging in high risk sex on a regular basis, the possibility that they were infected through health services must be investigated.

After all, there was an STI reduction program in Nairobi targetting sex workers in the early 1980s. As far as I know, this program did not target sex worker clients, which may well explain why HIV prevalence among men, in Nairobi and most other parts of Kenya, has never been as high as it has been among women.

Not only is it possible for HIV to be transmitted rapidly through unsafe health care, it is far more likely than transmission through unsafe sex. The transmission probability for many health practices is many times higher than the transmission probability for penile-vaginal sex.

Blood transfusions, for which the transmission probability is extremely high, may well have been made safer very early on in the epidemic. But most people don't have transfusions, whereas many people do receive injections and other invasive procedures. And the safety of these procedures has never been adequately assurred.

If these comments are even partly correct, not only is current UNAIDS policy allowing many people to become infected with HIV and other diseases; but it is also ensuring that many people become infected who might remain healthy if they ignore the health advice they are likely to receive. That's if they even have the option to ignore the advice.

Targeting STIs is a good thing in itself and may even reduce sexual transmission of HIV. But there is little point in reducing sexual transmission while at the same time increasing non-sexual transmission, especially that through unsafe injections and other procedures. HIV policy needs to follow health policy, not the other way around.


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