Pre-Exposure Prophylaxis or PrEP

Pre-exposure prophylaxis (PrEP) involves putting HIV negative people on antiretroviral drugs (ARV) with the aim of protecting them from HIV infection. This blog looks at some of the pros and cons of PrEP.

Friday, September 10, 2010

Beware of What We Don't Know About PrEP

It might be thought that if HIV were one day, not just preventable, but also curable, that prevalence in most countries would go down very quickly and anyone infected in the future would be cured, sooner or later.

But are all preventable diseases prevented, where possible? And are all curable diseases cured? Cholera, malaria, polio and a huge range of other diseases can all be prevented by provision of clean water and good sanitation and most of them are curable (although clean water is also required for this, not just drugs). Yet water-borne diseases are endemic in many countries and kill vast numbers of people. And polio, despite considerable efforts, some successful, just keeps coming back, to a large extent because people keep drinking water contaminated with sewage.

So why should pre-exposure prophylaxis (PrEP) for HIV be any different? Perhaps HIV is seen as politically important. Well, it certainly is politicized. But then, a massive cholera outbreak in Zimbabwe last year was also politicized. It received a lot of attention, one suspects, because Zimbabwe and Mugabe were receiving a lot of attention.

Cholera outbreaks are a reflection of very poor water and sanitation provision. The failure to deal with such an outbreak efficiently reflects badly on the strength of the country's administration and on the strength of their health services.

However, the cholera epidemic ceased to interest the world's media, perhaps because it eventually petered out, as epidemics sometimes do. Water and sanitation provision are unlikely to have been improved much, the same probably applies to health services. As for the administration, all that can be said is that the medial has gone off to ogle at something else.

How long will it take the world's media to focus on the current cholera outbreak in Nigeria? Perhaps the political situation is not considered interesting enough at the moment, but as a health story, it doesn't seem to have got around yet. Ok, the story is getting around now, but mostly among the African and NGO press. It has even appeared, briefly, in the mainstream media, but it has not been very widely covered, given the implications of such an epidemic.

When the media does get around to covering the outbreak, it will probably concentrate on the sheer magnitude, rather than the conditions that allowed the outbreak to become an epidemic. The media may even reflect on the irony of such an epidemic occurring when it's so easily predicted and prevented.

We know the conditions under which cholera outbreaks become epidemics, the determinants of such large scale health emergencies. We know how to substantially reduce the probability of such an outbreak and how to prevent it from escalating. You will find the perfect conditions for outbreaks of cholera and other water-borne diseases in most countries in Africa, right now.

'Emergencies' are not always unforeseen events. We might not know when and where they will occur but we always know the sort of places where they might occur, the conditions under which they will occur, given time. We usually have (or could easily obtain) a good idea of how many people are vulnerable to injury and death if they do occur and how to improve the conditions to the extent that an outbreak can be contained and people treated until their health is restored.

People needn't suffer from and die from many of the preventable and curable diseases that they do suffer and die from. But we also have the capability to provide HIV positive people with palliative care so they don't have to suffer unnecessarily, yet many don't receive such care. Many people who need antiretroviral drugs (ARV) either don't receive them or fail to keep on taking the drugs. In other words, many people suffer from and die from Aids, unnecessarily.

Even if HIV PrEP were a reality, and it is far from that, why should we believe that the practicalities of distributing such drugs to the people who need them, when they need them, for as long as they need them, will ever be part of the intention of those who keep screaming about how important PrEP is? Being able to do something is not the same as doing it, or having any intention of doing it.

If PrEP advocates would be a little honest and balanced in their arguments, I might give them some credence. But it is the very absoluteness of their pronouncements, the purity of their stated intentions, the apparent goodness and even the applicability of PrEP to the world that makes me think that the whole thing is part of a broader aim to vastly increase sales of relatively useless pharmaceutical products to people; any people at all.

One of the most worrying aspects of PrEP and HIV is that, unlike water-borne diseases, we don't know why such huge numbers of Africans become infected with HIV. We know that people who are members of some demographic groups in some countries are more likely to be infected than people from other demographic groups and countries. But we are not certain, despite assurances to the contrary, why this is so.

Everyone drinks water and most people have sex. Only some people drink contaminated water and only some are likely to have sex with a person who is HIV positive. But in most demographic groups in most countries, the likelihood of becoming infected with HIV, despite having regular, unprotected sex with someone who is HIV positive, is very low. Until we understand why this is so, PrEP will be of little use, if any, in high HIV prevalence countries.


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