Advocates of PrEP are probably as aware as anyone else that it hasn't yet shown much promise for men who have sex with men (MSM). It may not even be of much use in combination with other strategies (that also haven't shown much promise). But no one really wants to be the first to say that there is still a lot left to do, or admit that PrEP may end up in the broom cupboard.
Advocates still go back to their tack of 'sub-group analysis', taking the group that shows the best level of adherence to the drug and pointing out how effective it was for them. But high levels of adherence to PrEP could indicate other protective and risk avoidence practices, so care needs to be taken in interpreting this.
More importantly, levels of adherence in the group that shows the lowest levels of adherence could indicate that they engage in other risk behaviors and fail to take protective measures, adhering to PrEP just being one. Dr Joseph Sonnabend has discussed the folly of such analyses.
So these advocates of PrEP gathered around the ashes to figure out what to do and one of the questions they came up with was "what subset of men would be the most appropriate candidates for this new prevention tool?" Sonnabend's warning against sub-group analysis recommends an 'intention to treat analysis' as an alternative.
However, PrEP on an intention to treat basis would mean they would aim to put all MSM on the drugs. And then you have the problem that you will spend a lot of money for a miniscule return (if any). Even UNAIDS will start to notice if the effectiveness of PrEP doesn't improve considerably.
The group of advocates conclude that "PrEP is not a “magic bullet” and that it should not be viewed as the sole approach to reducing new HIV infections among MSM".
Exactly; they've also got a brand new roll of sticky tape, a stapler, a needle and some thread, a pot of glue and some thumb tacks, otherwise known as 'treatment 2.0'. So maybe they won't need the PrEP after all.
Showing posts with label post-exposure prophylaxis. Show all posts
Showing posts with label post-exposure prophylaxis. Show all posts
Monday, February 28, 2011
Sunday, February 6, 2011
In Case of Poor Health, Treat for HIV
Dr Joseph Sonnabend has a fascinating article on his blog about the original AZT trials, which notes that in the 1980s, many people with AIDS were dying of pneumocystis pneumonia, a preventable and treatable condition. That was in the US and other wealthy countries. But I suspect similar things are still happening in developing countries.
For example, sixty percent of people living with HIV in India are said to be dying of TB, a disease for which there are ample tests and drugs available. Dr Sonnabend notes a defeatist attitude in the 1980s but I don't think that attitude has lessened in resource poor countries.
In some countries, mothers are routinely treated with antiretroviral drugs to prevent transmission to their babies. But the health of the mothers themselves if often seen as being of little value compared to the life of their babies.
HIV positive mothers who give birth to HIV negative babies are not likely to be seen as a priority and may become sick and even die from preventable and curable illnesses. And if mothers die, the chances of their children suffering ill health and even of dying are significantly raised. Prioritizing the needs of their babies and ignoring the longer term needs of their mothers is extremely short sighted and even self-defeating.
In Kenya, I met a number of HIV positive people who subsequently died from TB or from undiagnosed conditions. AIDS was always blamed, but the people who died were usually on antiretroviral medication. Just because they were HIV positive, it was assumed that they were going to die and when they became very ill, there was often little available to them that they could afford.
Many of them had TB, which was sometimes being treated. But even people with TB are assumed to be HIV positive, although only about half the Kenyans with TB are also HIV positive. There is little said about the massive TB epidemic raging in Kenya, unless insofar as it is associated with HIV. But it's a very easily transmitted disease and it appears to spread independently of HIV just as efficiently as in conjunction with it.
The article about India continues: "though we have 12,500 microscopy centers available across India, deaths occur mainly due to late diagnosis, owing to technology limitations". In Kenya, the problem may be due to factors other than late diagnosis, for example, lack of facilities for diagnosis, lack of access to health facilities and lack of drugs for even very common conditions.
Distribution of HIV technologies always seems to have a lot more to do with markets than about need. And when all you have is a hammer, everything looks like a nail. There seems little point in treating people with expensive antiretroviral drugs and allowing recipients to suffer from and die from preventable and treatable conditions. But who am I to tell drug manufacturers how to maximize their profits?
[For more about HIV and health care, see my other blog, HIV in Kenya.]
For example, sixty percent of people living with HIV in India are said to be dying of TB, a disease for which there are ample tests and drugs available. Dr Sonnabend notes a defeatist attitude in the 1980s but I don't think that attitude has lessened in resource poor countries.
In some countries, mothers are routinely treated with antiretroviral drugs to prevent transmission to their babies. But the health of the mothers themselves if often seen as being of little value compared to the life of their babies.
HIV positive mothers who give birth to HIV negative babies are not likely to be seen as a priority and may become sick and even die from preventable and curable illnesses. And if mothers die, the chances of their children suffering ill health and even of dying are significantly raised. Prioritizing the needs of their babies and ignoring the longer term needs of their mothers is extremely short sighted and even self-defeating.
In Kenya, I met a number of HIV positive people who subsequently died from TB or from undiagnosed conditions. AIDS was always blamed, but the people who died were usually on antiretroviral medication. Just because they were HIV positive, it was assumed that they were going to die and when they became very ill, there was often little available to them that they could afford.
Many of them had TB, which was sometimes being treated. But even people with TB are assumed to be HIV positive, although only about half the Kenyans with TB are also HIV positive. There is little said about the massive TB epidemic raging in Kenya, unless insofar as it is associated with HIV. But it's a very easily transmitted disease and it appears to spread independently of HIV just as efficiently as in conjunction with it.
The article about India continues: "though we have 12,500 microscopy centers available across India, deaths occur mainly due to late diagnosis, owing to technology limitations". In Kenya, the problem may be due to factors other than late diagnosis, for example, lack of facilities for diagnosis, lack of access to health facilities and lack of drugs for even very common conditions.
Distribution of HIV technologies always seems to have a lot more to do with markets than about need. And when all you have is a hammer, everything looks like a nail. There seems little point in treating people with expensive antiretroviral drugs and allowing recipients to suffer from and die from preventable and treatable conditions. But who am I to tell drug manufacturers how to maximize their profits?
[For more about HIV and health care, see my other blog, HIV in Kenya.]
Wednesday, February 2, 2011
If You Need PrEP, You Probably Won't Receive It
Although not yet approved for use as a pre-exposure prophylaxis for men who have sex with men, CDC has issued guidelines for its use, a sort of de facto approval. But the guidelines make it clear that this is an expensive drug, intended for recreational use among those who can afford it. It's certainly not for people who live in the handful of African countries where HIV prevalence rates are the highest in the world.
For example, confirming that someone is at "substantial, ongoing, high risk for acquiring HIV infection" is going to be a bit of a challenge for the UNAIDS dominated prevention strategies in developing countries. As far as they are concerned, if someone is African and has sex, they are at high risk. The majority of infections occur among those engaging in what is essentially low risk sex. The contradiction doesn't bother UNAIDS.
Regular testing for those on PrEP is out of the question for most people in countries where most people are never tested and HIV positive people usually find out their status by the time their problem is AIDS rather than HIV. Similar remarks apply to regular sexually transmitted infection testing; poor countries don't have the health infrastructure to do this sort of work on large sectors of the population, even if they could identify which sectors those happen to be.
And so on. The measures recommended by CDC are pie in the sky for developing countries, where HIV prevalence wouldn't be nearly as high if they had such strong health services. And as for the remarks about adherence, the trial results cited completely fudge this issue. The overall 44% lower likelihood of acquiring HIV is constantly qualified by the higher figure achieved by those with high levels of adherence.
How about the lower figure for those who achieved the lowest level of adherence? People who fail to adhere to drug regimes or other measures that are intended to reduce risk of contracting HIV and other diseases are the very people who are at the highest risk. In other words, those least likely to adhere, and therefore to benefit from Truvada PrEP, are the ones who should be targeted. That's according to the guidelines, anyhow.
African populations are handy for testing out HIV drugs because there are very high levels of HIV transmission in many areas. But this drug is not intended for them. It is intended for those who wish to continue having risky sex but to minimize the risk of contracting HIV. The less risk they take, the better Truvada will work, but the less they will need it. The more risk they take, the worse Truvada will work and the more they will need it.
For example, confirming that someone is at "substantial, ongoing, high risk for acquiring HIV infection" is going to be a bit of a challenge for the UNAIDS dominated prevention strategies in developing countries. As far as they are concerned, if someone is African and has sex, they are at high risk. The majority of infections occur among those engaging in what is essentially low risk sex. The contradiction doesn't bother UNAIDS.
Regular testing for those on PrEP is out of the question for most people in countries where most people are never tested and HIV positive people usually find out their status by the time their problem is AIDS rather than HIV. Similar remarks apply to regular sexually transmitted infection testing; poor countries don't have the health infrastructure to do this sort of work on large sectors of the population, even if they could identify which sectors those happen to be.
And so on. The measures recommended by CDC are pie in the sky for developing countries, where HIV prevalence wouldn't be nearly as high if they had such strong health services. And as for the remarks about adherence, the trial results cited completely fudge this issue. The overall 44% lower likelihood of acquiring HIV is constantly qualified by the higher figure achieved by those with high levels of adherence.
How about the lower figure for those who achieved the lowest level of adherence? People who fail to adhere to drug regimes or other measures that are intended to reduce risk of contracting HIV and other diseases are the very people who are at the highest risk. In other words, those least likely to adhere, and therefore to benefit from Truvada PrEP, are the ones who should be targeted. That's according to the guidelines, anyhow.
African populations are handy for testing out HIV drugs because there are very high levels of HIV transmission in many areas. But this drug is not intended for them. It is intended for those who wish to continue having risky sex but to minimize the risk of contracting HIV. The less risk they take, the better Truvada will work, but the less they will need it. The more risk they take, the worse Truvada will work and the more they will need it.
Friday, January 28, 2011
Mixed Messages From CDC for Men Who Have Sex with Men
Apparently only 'high-risk' men who have sex with men should use Truvada as pre-exposure prophylaxis. Who are these high-risk men but those who tend not to take precautions? PrEP, if it works, is a precaution. Therefore, the only people likely to take PrEP as recommended would be considered to be low-risk.
But is Truvada really intended for those men who have sex with men who are at highest risk of HIV infection? I don't really believe that. I would suggest that Gilead, the manufacturers of Truvada, intend to break into the recreational drug market. I'd say they want people who don't wish to use condoms to use PrEP instead. I think that's what the whole pharmaceutical industry wants.
The US Center for Disease Control (CDC) has not approved the drug for preventive use. Yet they issue guidelines for its use as PrEP. Anyone can use Truvada if they can get hold of it and any doctor can prescribe it. I think we can be fairly certain that it will be prescribed and used as PrEP, as a recreational drug.
After all, people who are at high-risk of becoming infected, well, take risks. CDC not approving it as PrEP, but issuing guidelines, is not going to make people think twice. And whether Truvada results in "78% fewer cases of HIV infection" or reduces "infection by 44%" will make little difference to those who may already be engaging in have unprotected anal sex.
CDC and others are giving mixed messages and they seem to be doing so knowingly. If people listened to advice, they wouldn't be at high risk of being infected with HIV. Therefore, I suspect this whole scenario is calculated to maximize profits and minimize risk for the pharmaceutical industry and has little to do with the risk of contracting or transmitting HIV.
But is Truvada really intended for those men who have sex with men who are at highest risk of HIV infection? I don't really believe that. I would suggest that Gilead, the manufacturers of Truvada, intend to break into the recreational drug market. I'd say they want people who don't wish to use condoms to use PrEP instead. I think that's what the whole pharmaceutical industry wants.
The US Center for Disease Control (CDC) has not approved the drug for preventive use. Yet they issue guidelines for its use as PrEP. Anyone can use Truvada if they can get hold of it and any doctor can prescribe it. I think we can be fairly certain that it will be prescribed and used as PrEP, as a recreational drug.
After all, people who are at high-risk of becoming infected, well, take risks. CDC not approving it as PrEP, but issuing guidelines, is not going to make people think twice. And whether Truvada results in "78% fewer cases of HIV infection" or reduces "infection by 44%" will make little difference to those who may already be engaging in have unprotected anal sex.
CDC and others are giving mixed messages and they seem to be doing so knowingly. If people listened to advice, they wouldn't be at high risk of being infected with HIV. Therefore, I suspect this whole scenario is calculated to maximize profits and minimize risk for the pharmaceutical industry and has little to do with the risk of contracting or transmitting HIV.
Thursday, November 25, 2010
Is PrEP Destined to Be a Recreational Drug for Westerners?
There's a lot of excitement, not so surprising, about the results of a PrEP trial which took place among gay men and transgender women; it can cut new infections by at least 44%, those carrying out the research say. Thankfully, there are also cautioning voices, suggesting that there is a long way to go and that 44% in ideal conditions may not translate into 44% in non-trial conditions, the above article being one of the cautioning voices.
Presumably timed to coincide with World Aids Day on the 1st of December, this good news is likely to dominate the headlines for some time to come. I needn't go through the ins and outs of the trial, they are widely available. And there are even some good critiques that raise questions that need to be asked about an approach to a disease that depends entirely on some drugs.
Technologies such as antiretroviral treatment (ART) are great when they are used to prevent and treat a virus like HIV.But something that bothers me about HIV drugs is that the, arguably more important, objective of preventing HIV transmission by finding out what its determinants are and mitigating them has long gone out the window.
I have argued elsewhere that a significant amount of HIV transmission comes from unsafe medical practices. The WHO estimates a figure of 260,000, likely to be on the low side. No drug is required to prevent this so-called nosocomial (or iatrogenic) transmission of HIV. All that is required is good, affordable healthcare.
But there doesn't seem to be much appetite for providing people with what they really need. Single diseases have always had greater appeal and the exaggerated association of HIV transmission with sex continues to make it the biggest single recipient of health funding ever.
Sean Strub has an interesting article on post-exposure prophylaxis (PEP), antiretroviral drugs used after a suspected exposure to HIV has occurred. He has found that many people who should know about PEP don't. Although it has been widely available to healthcare workers in wealthier countries, and ostensibly in poor countries, it is not promoted widely enough among the many people who may face similar or even higher risks.
[For more information about PEP, have a look at the PEPnow site.]
I have talked to a lot of people in Kenya and Tanzania who should know about PEP but don't. This is inexcusable because PEP has been available for many years. But the fact that it is nowhere near as well known as it should be suggests to me that the current enthusiasm for PrEP is not because it could reduce and perhaps eventually eradicate the virus.
The fact that 'we' or 'science' or 'technology' can do something does not mean it will be done. 20% of deaths in under fives could be prevented by provision of clean water and sanitation, another 20% are caused by easily preventable and treatable respiratory infections. The vast majority of maternal deaths are also preventable.
Dare I suggest that developers of PrEP are more interested in the 'recreational' drug market? Something to reduce the risk of contracting HIV without the need for condoms or other precautions, perhaps?
Presumably timed to coincide with World Aids Day on the 1st of December, this good news is likely to dominate the headlines for some time to come. I needn't go through the ins and outs of the trial, they are widely available. And there are even some good critiques that raise questions that need to be asked about an approach to a disease that depends entirely on some drugs.
Technologies such as antiretroviral treatment (ART) are great when they are used to prevent and treat a virus like HIV.But something that bothers me about HIV drugs is that the, arguably more important, objective of preventing HIV transmission by finding out what its determinants are and mitigating them has long gone out the window.
I have argued elsewhere that a significant amount of HIV transmission comes from unsafe medical practices. The WHO estimates a figure of 260,000, likely to be on the low side. No drug is required to prevent this so-called nosocomial (or iatrogenic) transmission of HIV. All that is required is good, affordable healthcare.
But there doesn't seem to be much appetite for providing people with what they really need. Single diseases have always had greater appeal and the exaggerated association of HIV transmission with sex continues to make it the biggest single recipient of health funding ever.
Sean Strub has an interesting article on post-exposure prophylaxis (PEP), antiretroviral drugs used after a suspected exposure to HIV has occurred. He has found that many people who should know about PEP don't. Although it has been widely available to healthcare workers in wealthier countries, and ostensibly in poor countries, it is not promoted widely enough among the many people who may face similar or even higher risks.
[For more information about PEP, have a look at the PEPnow site.]
I have talked to a lot of people in Kenya and Tanzania who should know about PEP but don't. This is inexcusable because PEP has been available for many years. But the fact that it is nowhere near as well known as it should be suggests to me that the current enthusiasm for PrEP is not because it could reduce and perhaps eventually eradicate the virus.
The fact that 'we' or 'science' or 'technology' can do something does not mean it will be done. 20% of deaths in under fives could be prevented by provision of clean water and sanitation, another 20% are caused by easily preventable and treatable respiratory infections. The vast majority of maternal deaths are also preventable.
Dare I suggest that developers of PrEP are more interested in the 'recreational' drug market? Something to reduce the risk of contracting HIV without the need for condoms or other precautions, perhaps?
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