Roger Tatoud wonders out loud about medicalisation of sex in OpenDemocracy but I would be more worried about medicalisation of health. PrEP operates by putting HIV negative people on antiretroviral (ARV) drugs in the hope that this will reduce their susceptibility to the virus. And 'treatment as prevention' advocates claim that putting HIV positive people on ARVs will ensure that they are less likely to transmit the virus to HIV negative people.
Both processes are part of what some claim is a new paradigm. However, treatment is not prevention. It may play a part in prevention programs but it is not thereby a prevention paradigm. And PrEP is of little use without other prevention measures, such as condom use. In fact, condom use on its own is probably just as effective as condom use in conjunction with PrEP.
I've only managed to see the first page of an article by Vinh-Kim Nguyen and others, entitled 'Remedicalising an epidemic: from HIV treatment as prevention to treatment is prevention'. But they seem to be arguing something along similar lines.
Prevention has long been underfunded and transmission rates are not declining in many countries outside of Africa. As for the African countries with declining transmission rates, it is not really clear why they are declining. Declines in incidence started long before most prevention programs came into existence. This was also long before significant rollout of ARVs.
But a few tens of millions of HIV positive people is not a big enough market for the pharmaceutical industry, they have to put tens, or even hundreds, of millions of people on drugs even though they are not sick.
Showing posts with label treatment as prevention. Show all posts
Showing posts with label treatment as prevention. Show all posts
Monday, December 6, 2010
Monday, November 22, 2010
Will People Use Condoms With Pre-Exposure Prophylaxis or Microbicides?
A trial of combined condom and diaphragm use found that, although condom use increased during the trial, it returned to pre-trial rates afterwards. A commentator notes "What happens after trials has always remained very much a mystery". This appears to be true, and it's very disturbing.
Trial conditions are very different from non-trial conditions. Strict protocols are observed, at least in theory, so one would expect behavior to be substantially different once the intervention in question moves into the field. Especially when the trials show that the intervention only produced a small or temporary change in behavior. But results may even be a mere artefact.
Results of trials of mass male circumcision, microbicides (such as the tenofovir based gel tested in the CAPRISA trial), pre-exposure prophylaxis, test and treat strategies and other approaches to HIV prevention, which depend on the possibility of influencing sexual behavior, all share the risk of being artefacts.
Ariane van der Straten was involved in the Methods for Improving Reproductive Health in Africa project. This showed that, in many areas, the interventions involving diaphragms and lubricant, in addition to condoms and counselling employed for the control group, resulted in slightly higher rates of HIV transmission. However, the differences were not statistically significant.
Van der Straten points out that "it is a challenge to use concurrent HIV prevention methods, particularly barrier methods". All the technical solutions mentioned above require people to continue using condoms, even after circumcision and/or using microbicides or taking pre-exposure prophylaxis. Does she mean 'it is a challenge' or 'it is probably inadvisable'?
The study emphasised an unmet need for birth control, but this is hardly a surprise.
Van der Straten's concluding remark is particularly related to one of the assumptions about microbicides, though it may apply equally to pre-exposure prophylaxis. That is the claim that they are 'female-controlled'. Van der Straten says "In the past we have been naive, thinking that female-controlled methods could be used independent of men's involvement, but it's difficult to use any of these methods secretly, so there is a need to involve male partners in female-controlled methods so that they support their partners".
The full report is also freely available online.
Trial conditions are very different from non-trial conditions. Strict protocols are observed, at least in theory, so one would expect behavior to be substantially different once the intervention in question moves into the field. Especially when the trials show that the intervention only produced a small or temporary change in behavior. But results may even be a mere artefact.
Results of trials of mass male circumcision, microbicides (such as the tenofovir based gel tested in the CAPRISA trial), pre-exposure prophylaxis, test and treat strategies and other approaches to HIV prevention, which depend on the possibility of influencing sexual behavior, all share the risk of being artefacts.
Ariane van der Straten was involved in the Methods for Improving Reproductive Health in Africa project. This showed that, in many areas, the interventions involving diaphragms and lubricant, in addition to condoms and counselling employed for the control group, resulted in slightly higher rates of HIV transmission. However, the differences were not statistically significant.
Van der Straten points out that "it is a challenge to use concurrent HIV prevention methods, particularly barrier methods". All the technical solutions mentioned above require people to continue using condoms, even after circumcision and/or using microbicides or taking pre-exposure prophylaxis. Does she mean 'it is a challenge' or 'it is probably inadvisable'?
The study emphasised an unmet need for birth control, but this is hardly a surprise.
Van der Straten's concluding remark is particularly related to one of the assumptions about microbicides, though it may apply equally to pre-exposure prophylaxis. That is the claim that they are 'female-controlled'. Van der Straten says "In the past we have been naive, thinking that female-controlled methods could be used independent of men's involvement, but it's difficult to use any of these methods secretly, so there is a need to involve male partners in female-controlled methods so that they support their partners".
The full report is also freely available online.
Tuesday, November 9, 2010
Millions of Pills Haven't Worked So Let's Try Billions of Pills
The 'treatment as prevention' approach to reducing HIV transmission is getting airtime again, this time because the pioneer of the strategy has receive the Einstein award. Treatment as prevention is more of a hypothesis than a strategy or approach, really. But given the rarity of feasible HIV prevention strategies the HIV industry needs something to obsess about.
The hypothesis suggests that, because successful HIV treatment reduces the viral load to the extent that HIV positive people are very unlikely to transmit the virus, prevention programs could rely on this to significantly cut HIV transmission.
The number one flaw in the hypothesis is that it assumes that most HIV is transmitted sexually. This is a rash assumption in countries where health service provision is of extremely low quality. But the HIV industry has little interest in health or health service provision when they can sell lots of drugs. And it's a media friendly issue, with its combination of technical fix and the implication of illicit sex.
Of course, rolling out treatment to as many HIV positive people as possible when they need them is a good thing. But it may not have much impact on transmission rates. And ensuring that they didn't become infected in the first place would be preferable. It is hardly reassuring to those who are currently HIV negative that so little is going to be done to help them stay that way.
Another flaw is the assumption that a disease can be eradicated by some technical fix when the circumstances under which the disease became an epidemic are left pretty much as they are. So there is no need to improve health, education, infrastructure or social services? But these questions are not popular in the industry.
HIV testing has been around for some time now, in developed and developing countries. Most people never get tested, others test once and never again. But treatment as prevention requires the majority of people, or as near to 80% of people as possible, to be tested regularly, perhaps once a year.
It remains to be seen how many developing countries will be able to encourage such huge numbers of people to turn up for testing every year, or even how such programs will be administrated in countries where health services are so poor. High prevalence countries currently have a lot of trouble accounting for the HIV positive people they know about, a fraction of the total infected.
The above article on the award raises the issue of 'risk compensation', where it was feared that the availability of HIV treatment that also reduced infectiousness might result in increased risky sexual behavior. But where sexual behavior is not the main driver of HIV transmission, this is something of a red herring.
It's great to hear that treatment as prevention works so well in British Columbia. But I don't think the health problems in BC are anything like the health problems in East Africa. And I'm pretty sure the health systems (also education, social services, infrastructure) in BC are not like those in East Africa.
In short, the technology on its own is not the solution to an epidemic that has many determinants. This technical fix may have some impact in isolated pockets of East Africa, especially in randomized controlled trials, but people need a lot more than just pills to stay healthy. Far from obviating the need for decent health services now that some great technology is available, that technology requires adequate health services, and probably education, infrastructure and social services.
The hypothesis suggests that, because successful HIV treatment reduces the viral load to the extent that HIV positive people are very unlikely to transmit the virus, prevention programs could rely on this to significantly cut HIV transmission.
The number one flaw in the hypothesis is that it assumes that most HIV is transmitted sexually. This is a rash assumption in countries where health service provision is of extremely low quality. But the HIV industry has little interest in health or health service provision when they can sell lots of drugs. And it's a media friendly issue, with its combination of technical fix and the implication of illicit sex.
Of course, rolling out treatment to as many HIV positive people as possible when they need them is a good thing. But it may not have much impact on transmission rates. And ensuring that they didn't become infected in the first place would be preferable. It is hardly reassuring to those who are currently HIV negative that so little is going to be done to help them stay that way.
Another flaw is the assumption that a disease can be eradicated by some technical fix when the circumstances under which the disease became an epidemic are left pretty much as they are. So there is no need to improve health, education, infrastructure or social services? But these questions are not popular in the industry.
HIV testing has been around for some time now, in developed and developing countries. Most people never get tested, others test once and never again. But treatment as prevention requires the majority of people, or as near to 80% of people as possible, to be tested regularly, perhaps once a year.
It remains to be seen how many developing countries will be able to encourage such huge numbers of people to turn up for testing every year, or even how such programs will be administrated in countries where health services are so poor. High prevalence countries currently have a lot of trouble accounting for the HIV positive people they know about, a fraction of the total infected.
The above article on the award raises the issue of 'risk compensation', where it was feared that the availability of HIV treatment that also reduced infectiousness might result in increased risky sexual behavior. But where sexual behavior is not the main driver of HIV transmission, this is something of a red herring.
It's great to hear that treatment as prevention works so well in British Columbia. But I don't think the health problems in BC are anything like the health problems in East Africa. And I'm pretty sure the health systems (also education, social services, infrastructure) in BC are not like those in East Africa.
In short, the technology on its own is not the solution to an epidemic that has many determinants. This technical fix may have some impact in isolated pockets of East Africa, especially in randomized controlled trials, but people need a lot more than just pills to stay healthy. Far from obviating the need for decent health services now that some great technology is available, that technology requires adequate health services, and probably education, infrastructure and social services.
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