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.

Wednesday, October 27, 2010

Are Healthy People More Likely to Take Drugs than Unhealthy People?

Loss to follow up is a common problem with HIV treatment programs and up to 40% of East Africans may cease to collect their drugs at some time. They may have gone somewhere else or died, but it's hard to tell. Records are not always well kept.

It's hard to know how good people will be at taking drugs to prevent HIV, as opposed to those that treat HIV. Early papers on adherence seemed keen to report good news, that people in developing countries were even likely to be better at keeping to treatment regimes than people in rich countries. But later papers have not always been so optimistic.

I have seen several mentions recently of people preferring to pray and believe that God will save them, keep them alive, 'cure' them of HIV, etc. People who believe this don't always stop their treatment, although some do. But even temporary lapses in taking antiretroviral drugs can cause problems such as opportunistic illnesses and resistance build up.

I have even come across people who have insisted that praying is the best response because God will decide, whatever the outcome is. This is disturbing to witness, especially when one suspects that many people taking this view also seem to associate HIV with some kind of evil or sin.

A recent article suggests that some young people in Uganda are being persuaded to give up taking Aids drugs and relying on their beliefs instead. Some of those persuading them are possibly not even genuine pastors, though it seems equally inexcusible whether they are genuine or not.

Proponents of PrEP tend to ignore the potential problems of ensuring that people who are not sick take drugs as required in order to prevent infection with HIV. Especially as research into exactly how most HIV is transmitted in high prevalence countries is thin on the ground.


Sunday, October 24, 2010

Never Mind Efficacy, Think of the Profits

There's an interesting article in the Emerging Health Threats Forum about bird flu behavior change campaigns and people's perception of risk. It was found that "People who witness avian flu outbreaks in animals near them fear the disease less than those with no experience of it".

Most HIV prevention campaigns have attempted to influence people's sexual behavior by warning them about certain risks and telling them how to avoid them. Some of these campaigns have been assessed and the results tend to show that many people continue with the behaviors considered to be risky.

Speculation has suggested that HIV transmission rates in Uganda, and eventually in some other countries, started to decline once people realized that many of those around them were becoming sick and dying. This is unlikely to be true because high death rates would have occurred some years after declines in transmission started.

However, much HIV prevention work continues with the assumption that people will modify risky behavior once they know that it is risky and what steps they can take to ensure that they don't become infected. And perhaps the assumption is, to some extent useful. Perhaps people will eventually begin to take precautions and the bulk of sexual transmission of HIV will be eradicated.

Wide availability of PrEP in high HIV prevalence countries may become a 'protective' behavior, something people who cannot avoid sexual risks can take to reduce the risk of infection. In textbook cases, where HIV transmission really does occur because people are taking unnecessary and avoidable sexual risks, PrEP may even have a substantial effect on sexual transmission.

Unfortunately, a good deal of sexual transmission is probably not of the textbook variety. The incredibly high rates of risky sexual behavior attributed to Africans in the textbooks are more likely to be a widely shared fantasy, stubbornly held by those who are in the best position to see how such views are completely without foundation.

But even where PrEP is available to prevent some sexual HIV transmission, it is unlikely to have any impact on non-sexual HIV transmission. The fact that UNAIDS and other institutions are not even targeting non-sexual transmission doesn't help, but giving out pills, to however many people, is not the most expeditious means of reducing, for example, health care related exposure to HIV.

It is not a new discovery that behavior and behavior change are complicated and difficult to effect. And this is not to say that some kinds of behavior change shouldn't be attempted and facilitated. However, concentrating all our attention on sexual HIV transmission, without even attempting to find out how much of the virus is spread though non-sexual modes, results in an unknown level of avoidable infection.

PrEP may hold some promise for certain kinds of sexually transmitted HIV but it will not eradicate the virus. And it will have little or no impact on non-sexual transmission, which is probably responsible for a large proportion of the highest prevalence epidemics, all of which are found in a handful of sub-Saharan African countries.

Some advocates of PrEP may truly believe that it could eventually play a part, perhaps a big part, in eradicating the virus. People who believe this don't know very much about HIV. But I suspect that PrEP is just a clever way of increasing HIV drug sales by several hundred percent, perhaps even several thousand percent.

Having a ready supply of trial participants in countries where the virus is common will help a lot in getting the drugs on the market. Meanwhile, epidemics in African countries continue on trajectories that are completely independent of any HIV prevention programs that have taken place so far.


Thursday, October 21, 2010

Gates Foundation Spends Billions on Potemkin Villages

Bill and Melinda Gates seem to think people have a downer on development aid, if their recent attempts to present us with 'success stories' is anything to go by. One of problems with Gates and Co is that they have a lot of say in how the development agenda is set because they have the money to blow on whatever they feel like. So if they feel like blowing their money on puffing their own projects and interests, they'll do it. And if they feel like hyping PrEP, genetically modified organisms and numerous other purely technical quick fixes, they'll do that.

In recent years, questions have been raised about the way things have been done in development up to now. Perhaps that was going nowhere and things will just continue to benefit the donors more than people living in developing countries. But what the Gates Foundation is doing tends to obscure what is going on, to paint a colorful picture when what we need is an accurate picture. Worse still, because they get to set the agenda, issues that have been ignored in the past will stay in the dark and issues that these over paid bureaucrats like will be even more hyped than before.

Nothing I read about Gates and his cronies makes me think that he understands poverty or any other issue in development. I don't even think he cares very much about such things. I have no idea what motivates him but I don't see him engaging with anything but opportunities to force unneeded and possibly harmful technologies on people who are too disempowered to object. The foundation's work risks undermining other work that is going on in development and unless they can learn to cooperate and even take their lead from people who know what they are doing, who know what they are talking about, development will be stifled.

For example, PrEP is not going to reduce the risks that HIV negative people face to any great extent. People who face sexual risks can take other measures and if they can't, it's hard to see how some pills with help. For those who face non-sexual risks, the pills may work, but their availability is not a reason for allowing unsafe medical and other practices to continue. PrEP is in danger of sweeping the real problems under the carpet, but without reducing the risks appreciably.

Genetically modified organisms and other technical quick fixes are similarly distracting from the real issues that give rise to poverty, food insecurity, contaminated water and poor sanitation, inequalities of various kinds and any other development problems. Technical solutions are in the hands of technocrats like Gates and they will always remain in the hands of the rich and powerful. People don't die for want of pills for, say, cholera, they die for want of fresh water. Cure cholera and a handful of other water borne diseases and people will die of something else, probably also water borne.

The majority world is not a sand-pit for Gates and recipients of his largesse to play in, it is reality for most of the world's population. Big 'philanthropy' needs to be answerable to the public before it does irreparable damage, if it hasn't done so already.


Tuesday, October 12, 2010

If We Could Eradicate HIV, Would We?

I'm amazed at the enthusiasm for a program to distribute massively expensive drugs to people to prevent a disease that is difficult to transmit sexually, when the proposed targets are chosen by reference to their sexual behavior (or their assumed sexual behavior). Especially when funding for antiretroviral programs is being cut, even for people already on treatment.

But the really amazing thing is how many people suffer from preventable and treatable conditions, such as parasites. The numbers of people run into hundreds of millions, even billions. Yet the drugs to prevent, treat and completely eradicate these illnesses have been around for decades and cost very little. Examples are lymphatic filiarisis (elephantiasis), schistosomiasis (bilhartzia) and onchocerciasis.

In fact, many of the things that people in developing countries suffer from the most and die from most often are also easily preventable and treatable. Most relate to poor living conditions and lack of or no access to clean water and sanitation. In other words, the majority of people need very low tech solutions, which are also basic human rights, without which people's lives will be blighted and most will eventually die unnecessarily, or unnecessarily early.

It seems there are few arguments for rolling out a very expensive program that may possibly prevent a small number of transmissions of a virus that infects a relatively small number of people until the far easier and cheaper jobs that will save billions of people have been accomplished first.


Sunday, October 10, 2010

HIV Still Holds Good Opportunities for Investors

A worrying aspect of the ever increasing medicalization of health, including HIV/AIDS and other diseases that are especially common in developing countries, is the question of how the commodities involved will be paid for. Many people advocating the greater use of drugs, perhaps most, have an interest of some kind, financial, political, career related, perhaps all of these.

But the fact is, people in developing countries can not pay for expensive commodities. And there's no reason why they should do so when their most urgent needs are not commodities, they are basic human rights, such as food, water and sanitation, basic health services, education, infrastructure and other social services. People don't generally die for want of expensive medication, though they often die for want of very cheap medication, medication which is too cheap for Big Pharma to be interested in.

Protesters in India have been arrested for arguing that the European Union (EU) is threatening the production and use of cheap generic drugs by hoodwinking India into signing a 'Free' Trade Agreement (FTA), which will 'allow' India to export some of its products in greater quantities to Europe, but at derisory prices. In reality, the agreement is so that European countries can export their overpriced goods, often goods that are only likely to benefit wealthier Indians, to a country that has no need of these goods.

Medicins Sans Frontieres is running a campaign to prevent the EU from abusing its power in this way (email the EU trade commissioner to protest!). The FTA would apply to all drugs, whether intended for primary health or otherwise, whether lifesaving or not. It would also apply to all other goods and the conditions go beyond what is required by the World Trade Organization's Trade Related Aspects of Intellectual Property Rights agreement (TRIPS). Those who naively support the greater use of PrEP could take a little time to consider if such a strategy would really benefit people who are most at risk of HIV infection.


Friday, October 8, 2010

Drop Everything, A Vaginal Gel Has Been Developed

Chi Mgbako writes an article entitled "International donors must fund female-controlled HIV prevention gel", but this raises a number of issues.

Is a vaginal gel, as Mgbako and others argue, female controlled? One would think that if it is, so are oral contraceptives. Yet, the majority of women in many developing countries opt for injectible contraceptives. They say their husbands object to them taking contraceptives, so they get an injection every three months, possibly running the risk of picking up some blood-borne infection at the clinic, perhaps even HIV. Will the same husbands that object to oral contraceptives ignore vaginal gels? Has this even been tested?

Also, this article mentions a number of things that are in need of change, such as domestic violence and gender inequality. These are in need of change regardless of HIV transmission. Is the author advocating that these and other social problems be ignored as long as vaginal gel is paid for by international donors and some (rather small) percentage of HIV infections are possible prevented?

I don't think the author is making the argument that these other social problems are insignificant or that HIV reduction should be chosen over other social problems. Rather, it needs to be made clear that that is something international donors do.

Numerous social problems have been alluded to as causing HIV transmission, allowing HIV transmission, assisting HIV transmission, etc. But most of these problems are independent of HIV, they existed before HIV and they won't just go away on their own.

But HIV programs have a tendency to ignore contexts to the extent that HIV testing clinics are set up in areas where people are dying of contaminated water related diseases, respiratory infections, intestinal parasites and other treatable and preventable conditions. HIV programs are, no matter how much those in the HIV industry would like to argue otherwise, deflecting attention from real and preventable problems.

And to what end? That we might be able to reduce HIV transmission by 39% (in ideal, trial related scenarios)?

Finally, if the gel is so good, why have funders not come up with the funding? Is there something they know that we are not allowed to know? Other HIV related drugs have made billions, why are international funders drawing back from this one?


Tuesday, October 5, 2010

Some Disturbing Considerations Relating to PrEP Trials

Anyhow, the article notes that “Behavioural messages that encourage abstinence, monogamy and use of condoms have had […] only a limited long-term impact on the spread of HIV in that region.” The article calls for HIV prevention strategies to be made relevant, though they are not talking about making them relevant to the possibility that some HIV is not sexually transmitted.

A popular claim about PrEP (and other technological fixes) is that they can be applied by women and are “under their control”. There may be some truth in this. Yet, oral contraception has long been available without most women choosing to avail of it. Many instead opt for injectable versions, thus putting themselves at higher risk of being infected with HIV and other viruses as a result of unhygienic health practices.

Injectable versions of contraception are very popular with married women and sex workers, though perhaps for different reasons. Married women say they are not willing to risk having their husband interfere if they keep oral contraceptives at home, which they have to take regularly. It remains to be seen whether attitudes towards PrEP gel are any different. Is it really ‘under the control of women’?

The question is pertinent because unsafe health care practices are not under any clients control, whether male or female. People might be able to take precautions but they have to know that such practices could lead to infection and they have to know what they can do to protect themselves. The HIV/AIDS industry, in this instance, doesn’t seem to be interested in the strategy being under the control of those who face the risks.

The CAPRISA 004 trial, despite widely repeated claims, did not establish what risks were reduced among those taking part. Was it just the risk of sexual transmission that was reduced or was it also the risk of non-sexual transmission? The difference is crucial.

The article notes that the trial results were not affected by frequency of sex. But sexual activity was not very high during the trial and it decreased over time, as did use of the Tenofovir gel. However, HIV transmission over the course of the trial was extremely high, even among the intervention group.

It is also noted that “average viral load was not significantly different” between the intervention and control groups. The ‘Test and Treat’ strategy, which was being hyped as much as PrEP two years ago, claims that placing every HIV positive person on antiretroviral drugs will reduce viral load and therefore reduce transmission. But there is now evidence that low viral load may not be so closely related to rates of HIV transmission, something I have recently discussed on my other blog, HIV in Kenya.

The Aegis article warns that the results need to be viewed with caution; this can not be stressed enough. These trials, CAPRISA 004 in particular, seem to take little notice of how HIV might be transmitted among the populations taking part in their research. If HIV is not all transmitted sexually, such trials will continue to produce invalid results and people will continue to be exposed unnecessarily to the risk of infection with HIV and other blood-borne viruses.