Researchers in South Africa aiming to estimate how many pregnant women were in the 'acute' phase of HIV infection, where their status would be undetectable using ordinary HIV tests, found that an astonishing 38% of women were HIV positive. They estimate the yearly rate of infection at over 11%.
It doesn't take a genius to work out that at these rates, the majority of women will be infected or dead from AIDS by the time they are in their thirties. These rates may have been found elsewhere, but they are still shocking. And yet, these researchers seem to think that they will achieve something by testing more and more people with better and better testing methods.
How are they being infected? The article assumes that most transmission is through heterosexual sex but this is just not credible. Some of the women were very young, they would hardly have had enough time to have enough sexual experience to become infected with a virus that is difficult to transmit through penile-vaginal sex.
If they are being infected by HIV positive men, who are these men? Incidence among men of similar age is often ten or more times lower. While it is argued that young women have sex with older men, who are more likely to be infected, are there even enough older HIV positive men to explain incidence figures among women? And are these women having sex with them? These have never been demonstrated.
Earlier research in South Africa has suggested that the probability of transmission is often 1, that a woman can become infected despite having only one partner and possibly even only having unprotected sex once. Would the researchers like to claim that there is a different strain of HIV in South Africa? Has the possibility of such transmission rates through heterosexual intercourse ever been demonstrated?
I don't believe so. I believe a lot of things are assumed, despite evidence to the contrary. And the authors of this paper go on making those assumptions. But HIV transmission will not be prevented if we don't even know how it is occurring. Rather than establishing how they may have become infected, it is assumed that most African women were infected sexually and conveniently forgotten that the chances of this happening to a few women, let alone to many, are extremely low.
Non-sexual HIV transmission must be considered. Most women, African and non-African, even young women, do not take stupid risks when they are pregnant. Most women don't take stupid risks even when they are not pregnant. Many HIV infections among pregnant women occur once they are already pregnant, often long into their pregnancy.
Transmission rates may well be higher among pregnant women, but so is the number of risks they face from being infected through unsafe injections or other medical procedures. And interestingly, the percentage of women in South Africa who visit an ante-natal clinic several times during their pregnancy is in the 90s. Compare that to a country like Tanzania, where some may visit once but the majority never visit at all, and where rates of transmission are many times lower than in South Africa.
Is it just a coincidence that HIV rates are often lower in areas where people don't have access to health services? Perhaps it is. But it is vital to find out if it is a coincidence. If it isn't a coincidence, then health services could be busy spreading the very virus they are supposed to be preventing.
Showing posts with label mother to child transmission. Show all posts
Showing posts with label mother to child transmission. Show all posts
Thursday, January 20, 2011
Sunday, October 17, 2010
Why Do UNAIDS Only Wish To Eliminate Some HIV Infections, And Not All?
Writing in the Huffington Post last month, Susan Smith Ellis paints a rosy picture for the future of prevention of HIV transmission from mothers to their children. Ellis's claim that this form of HIV transmission can be eliminated entirely by 2015 may well be true. But it is very unlikely that the goal will be achieved in high prevalence countries. And most of the 430,000 children a year, either born with HIV or becoming infected with it in their first few months of life, are from sub-Saharan African countries.
The HIV orthodoxy, led by UNAIDS, assumes that almost all HIV infection in African countries, around 90%, is a result of (unsafe) heterosexual sex. This assumption is not supported by evidence. Rather, mathematically modeled figures are used to support a set of prejudices that deny the possibility that non-sexual transmission occurs to any great extent in African countries.
It would be very foolish to claim that HIV is never sexually transmitted, or is hardly ever sexually transmitted. But it is no more foolish than claiming that HIV is never transmitted non-sexually. The virus is almost certainly transmitted both sexually and non-sexually. What is in question is the contribution that each mode of transmission makes to HIV epidemics in high prevalence countries.
There is evidence that sexual behavior differs greatly between high prevalence countries (or high prevalence regions in high prevalence countries), but the evidence is weak and doesn't stand up to scrutiny. In contrast, the evidence that health services in high HIV prevalence countries are poor, and could be responsible for some of the highest rates of HIV transmission, is more difficult to refute.
Rather than attempt to refute evidence that HIV may commonly be transmitted through unsafe healthcare, UNAIDS and others simply deny its existence. Occasionally, they refer to non-sexual transmission, either to stress how low it is in high prevalence countries or to warn UN employees to avoid using health facilities in high HIV prevalence countries. But their mantra is one of personal responsibility, of avoidable HIV transmission through unsafe sex.
If a woman is infected with HIV on or around the time of conception, her HIV status can be confirmed by a test some time round the end of the first trimester. If infection occurred before the time of conception, the test will confirm the woman's HIV status, but it won't confirm when infection took place. Yet the woman may not have been sexually active before the time of conception, or she may have taken precautions against both conception and infection. However, because she is pregnant, it will probably be assumed that she was infected sexually.
Perhaps it sounds reasonable to assume that the woman was infected sexually, but was her partner HIV positive? It is not routine in most health facilities to check. It can happen that the partner is tested but it very often doesn't. And given how much lower HIV rates are among men, there is a good chance that most HIV positive pregnant women were not infected by their partner (and it appears to be common for women to give birth to a child fathered by their partner). In fact, in Kenya, around 50% of married HIV positive women have a HIV negative partner.
Do we just assume that all these women also had sex with some HIV positive man, despite the fact that he was not their partner and despite the fact that most or all of them say they have only ever had sex with their partner? If we work for UNAIDS and many other organizations, that is pretty much what we assume. We assume that she is not only promiscuous, but that her word is not reliable. (There is also the mystery of how she became infected with HIV by someone who managed not to impregnate her. It's an awful lot easier to get pregnant than to be infected with HIV through unsafe sex.)
For many women, things are more complicated. They are infected in their second or even third trimester. They may be tested and found to be positive, which makes treatment, or at least precautions against mother to child transmission, more likely. But they may be infected so late in their pregnancy that their positive status is not detectable until after they deliver. In such cases, the need for treatment may not be discovered until it is too late, it may not even be discovered at all.
There are many other aspects to this area of HIV prevention but the aspect I wish to draw attention to is the assumption that most HIV transmission is sexual. Where this assumption is made, other modes of transmission are ignored. Pregnant women and babies receive a lot of medical procedures that men do not receive. One would hope that these medical procedures are safe and hygienic, that they do not pose any risk of infecting either the mother or the child.
But there is no such guarantee in many countries. Conditions in health facilities may be better than conditions in people's homes, but where conditions have been evaluated, they can be very poor indeed. Hospitals often lack personnel with the requisite training, equipment, hygiene procedures and other things that eliminate or reduce the risks of transmission of HIV or other blood borne diseases. Conditions at home are less likely to include the risk of infection with a serious virus, such as hepatitis or HIV. But equipment that is contaminated with these viruses could be common in health facilities. After all, sick people tend to go to hospitals if they can.
We don't need to assume that HIV is almost always transmitted sexually. Sexual behavior, indeed, should be irrelevant to health facility safety. Even mothers who are, or whose partners are, 'promiscuous' or engage in 'unsafe' sex, is not really the issue. The issue is whether the health care they receive is likely to expose mothers and babies to the risk of nosocomial HIV transmission, transmission through unsafe medical procedures. What countries with high HIV prevalence need is greater vigilance in health facilities and an admission that blood-borne infections can occur, just like they can, and often do, in rich countries.
And that's why Susan Smith Ellis is wrong in claiming that, because mother to child transmission of HIV could be eliminated, that it will be eliminated. As long as the assumption is made that the risk is almost all sexual and hardly ever non-sexual, and especially health care related, mothers and their babies will continue to be exposed to risks; many will be infected. Probably the biggest demographic group in high prevalence countries, sexually active women who are having children, are currently facing an avoidable risk, a risk that UNAIDS insists does not exist.
The HIV orthodoxy, led by UNAIDS, assumes that almost all HIV infection in African countries, around 90%, is a result of (unsafe) heterosexual sex. This assumption is not supported by evidence. Rather, mathematically modeled figures are used to support a set of prejudices that deny the possibility that non-sexual transmission occurs to any great extent in African countries.
It would be very foolish to claim that HIV is never sexually transmitted, or is hardly ever sexually transmitted. But it is no more foolish than claiming that HIV is never transmitted non-sexually. The virus is almost certainly transmitted both sexually and non-sexually. What is in question is the contribution that each mode of transmission makes to HIV epidemics in high prevalence countries.
There is evidence that sexual behavior differs greatly between high prevalence countries (or high prevalence regions in high prevalence countries), but the evidence is weak and doesn't stand up to scrutiny. In contrast, the evidence that health services in high HIV prevalence countries are poor, and could be responsible for some of the highest rates of HIV transmission, is more difficult to refute.
Rather than attempt to refute evidence that HIV may commonly be transmitted through unsafe healthcare, UNAIDS and others simply deny its existence. Occasionally, they refer to non-sexual transmission, either to stress how low it is in high prevalence countries or to warn UN employees to avoid using health facilities in high HIV prevalence countries. But their mantra is one of personal responsibility, of avoidable HIV transmission through unsafe sex.
If a woman is infected with HIV on or around the time of conception, her HIV status can be confirmed by a test some time round the end of the first trimester. If infection occurred before the time of conception, the test will confirm the woman's HIV status, but it won't confirm when infection took place. Yet the woman may not have been sexually active before the time of conception, or she may have taken precautions against both conception and infection. However, because she is pregnant, it will probably be assumed that she was infected sexually.
Perhaps it sounds reasonable to assume that the woman was infected sexually, but was her partner HIV positive? It is not routine in most health facilities to check. It can happen that the partner is tested but it very often doesn't. And given how much lower HIV rates are among men, there is a good chance that most HIV positive pregnant women were not infected by their partner (and it appears to be common for women to give birth to a child fathered by their partner). In fact, in Kenya, around 50% of married HIV positive women have a HIV negative partner.
Do we just assume that all these women also had sex with some HIV positive man, despite the fact that he was not their partner and despite the fact that most or all of them say they have only ever had sex with their partner? If we work for UNAIDS and many other organizations, that is pretty much what we assume. We assume that she is not only promiscuous, but that her word is not reliable. (There is also the mystery of how she became infected with HIV by someone who managed not to impregnate her. It's an awful lot easier to get pregnant than to be infected with HIV through unsafe sex.)
For many women, things are more complicated. They are infected in their second or even third trimester. They may be tested and found to be positive, which makes treatment, or at least precautions against mother to child transmission, more likely. But they may be infected so late in their pregnancy that their positive status is not detectable until after they deliver. In such cases, the need for treatment may not be discovered until it is too late, it may not even be discovered at all.
There are many other aspects to this area of HIV prevention but the aspect I wish to draw attention to is the assumption that most HIV transmission is sexual. Where this assumption is made, other modes of transmission are ignored. Pregnant women and babies receive a lot of medical procedures that men do not receive. One would hope that these medical procedures are safe and hygienic, that they do not pose any risk of infecting either the mother or the child.
But there is no such guarantee in many countries. Conditions in health facilities may be better than conditions in people's homes, but where conditions have been evaluated, they can be very poor indeed. Hospitals often lack personnel with the requisite training, equipment, hygiene procedures and other things that eliminate or reduce the risks of transmission of HIV or other blood borne diseases. Conditions at home are less likely to include the risk of infection with a serious virus, such as hepatitis or HIV. But equipment that is contaminated with these viruses could be common in health facilities. After all, sick people tend to go to hospitals if they can.
We don't need to assume that HIV is almost always transmitted sexually. Sexual behavior, indeed, should be irrelevant to health facility safety. Even mothers who are, or whose partners are, 'promiscuous' or engage in 'unsafe' sex, is not really the issue. The issue is whether the health care they receive is likely to expose mothers and babies to the risk of nosocomial HIV transmission, transmission through unsafe medical procedures. What countries with high HIV prevalence need is greater vigilance in health facilities and an admission that blood-borne infections can occur, just like they can, and often do, in rich countries.
And that's why Susan Smith Ellis is wrong in claiming that, because mother to child transmission of HIV could be eliminated, that it will be eliminated. As long as the assumption is made that the risk is almost all sexual and hardly ever non-sexual, and especially health care related, mothers and their babies will continue to be exposed to risks; many will be infected. Probably the biggest demographic group in high prevalence countries, sexually active women who are having children, are currently facing an avoidable risk, a risk that UNAIDS insists does not exist.
Saturday, April 17, 2010
Health Aid: Supporting People or Supporting Indicators?
While news that maternal mortality has been decreasing since 1980 has been welcomed by many, others point out that a significant contributor to maternal mortality is HIV. A lot of attention and resources go towards mother to child transmission of HIV (MTCT), but very little go towards the health and survival of the mothers. Concentration on the single indicator of numbers of infants infected by their mothers, also called vertical transmission, seems to have left the health of HIV positive mothers out of the picture.
Of course, it is madness to ignore the HIV status of the mother, for many reasons. For a start, mothers are people too, not just 'cases' or carriers of disease. They, like their children, husbands and other family members, are entitled to health and to treatment when their health is compromised. And it would be madness too to ignore any other diseases, in mothers and children or anyone else. But health funding is mad. Hence the selection of a few headline grabbing indicators.
HIV positive mothers can go on to transmit HIV to their infants at a later stage, through various routes, or to their partners. They are at risk of dying from Aids related illnesses or of suffering from serious and prolonged illnesses. These will also have an impact on the health of their children and other family members. Even the MTCT prevention treatment (PMTCT) can lead to drug resistance in mothers. In developing countries this can seriously affect the chances of the mother being successfully treated or cut the length of time that the treatment remains effective.
It seems extraordinary that health funders still take this piecemeal approach to disease reduction, even when it directly affects their chosen indicator(s). Unsurprisingly, the report was funded by the Gates Foundation. They particularly favour somewhat rarefied approaches to health issues, selecting the bits that they are interested in and leaving the rest. For example, the foundation is interested in finding a vaccine for cholera but not so interested in clean water and sanitation, which could reduce incidence of numerous water related health issues. (They give small amounts of money to water and sanitation projects but nothing like the amount going to vaccines and the like.)
A particularly worrying aspect of approaching MTCT in this piecemeal fashion is that as many as half of infant infections may result from mothers who were infected while they were pregnant or whose positive status was not detected while they were pregnant (perhaps because they were in the 'window' period, where they had not yet seroconverted). This occurred in a PMTCT programme in Malawi, considered to be one of the best. Another survey found that such missed maternal HIV infections resulted in a high percentage of infants being born HIV positive. Ironically, the paper also concludes that recently increased child mortality rates in KwaZulu-Natal could be caused, in part, by increased maternal mortality.
It has been suggested that this may be a potentially useful role for pre-exposure prophylaxis (PrEP). PrEP involves putting HIV negative people on antiretroviral drugs, usually where they are thought to be at particular risk of infection. Of course, some of these women may not have been infected through sexual intercourse. It is not even clear from the article whether the mothers of infants subsequently found to be HIV positive were also re-tested or were just assumed to be positive because their infants were. Apparently, an unusually high percentage of women who were not found to be HIV positive before delivery were later found to have HIV positive infants.
Concentrating on one disease or on that disease in one demographic, or even looking at absence of sickness as the only criterion for health, is not going to ensure the health of whole populations. The dominant approach to HIV and the almost universal adherence to the behavioural paradigm (the view that the disease is predominantly sexually transmitted) is wrong for many reasons that have been made clear, in particular, by our lack of success in significantly slowing the pace of transmission. It's time to look at HIV as being part of health as a whole, as being related to the totality of conditions in which people live and work.
If we continue to fail to ensure good health services, education, nutrition levels, food security, infrastructure and numerous other conditions, all diseases, including HIV, will continue to spread. This will reduce people's quality of life and life expectancy. Self serving reports that show how well some favoured indicator is doing should be seen for what they are. Billions of people still suffer from and die from preventable and treatable diseases every year. That's nothing to celebrate.
(For further discussion of PrEP, see my other blog, pre-exposureprophylaxis.blogspot.com)
Of course, it is madness to ignore the HIV status of the mother, for many reasons. For a start, mothers are people too, not just 'cases' or carriers of disease. They, like their children, husbands and other family members, are entitled to health and to treatment when their health is compromised. And it would be madness too to ignore any other diseases, in mothers and children or anyone else. But health funding is mad. Hence the selection of a few headline grabbing indicators.
HIV positive mothers can go on to transmit HIV to their infants at a later stage, through various routes, or to their partners. They are at risk of dying from Aids related illnesses or of suffering from serious and prolonged illnesses. These will also have an impact on the health of their children and other family members. Even the MTCT prevention treatment (PMTCT) can lead to drug resistance in mothers. In developing countries this can seriously affect the chances of the mother being successfully treated or cut the length of time that the treatment remains effective.
It seems extraordinary that health funders still take this piecemeal approach to disease reduction, even when it directly affects their chosen indicator(s). Unsurprisingly, the report was funded by the Gates Foundation. They particularly favour somewhat rarefied approaches to health issues, selecting the bits that they are interested in and leaving the rest. For example, the foundation is interested in finding a vaccine for cholera but not so interested in clean water and sanitation, which could reduce incidence of numerous water related health issues. (They give small amounts of money to water and sanitation projects but nothing like the amount going to vaccines and the like.)
A particularly worrying aspect of approaching MTCT in this piecemeal fashion is that as many as half of infant infections may result from mothers who were infected while they were pregnant or whose positive status was not detected while they were pregnant (perhaps because they were in the 'window' period, where they had not yet seroconverted). This occurred in a PMTCT programme in Malawi, considered to be one of the best. Another survey found that such missed maternal HIV infections resulted in a high percentage of infants being born HIV positive. Ironically, the paper also concludes that recently increased child mortality rates in KwaZulu-Natal could be caused, in part, by increased maternal mortality.
It has been suggested that this may be a potentially useful role for pre-exposure prophylaxis (PrEP). PrEP involves putting HIV negative people on antiretroviral drugs, usually where they are thought to be at particular risk of infection. Of course, some of these women may not have been infected through sexual intercourse. It is not even clear from the article whether the mothers of infants subsequently found to be HIV positive were also re-tested or were just assumed to be positive because their infants were. Apparently, an unusually high percentage of women who were not found to be HIV positive before delivery were later found to have HIV positive infants.
Concentrating on one disease or on that disease in one demographic, or even looking at absence of sickness as the only criterion for health, is not going to ensure the health of whole populations. The dominant approach to HIV and the almost universal adherence to the behavioural paradigm (the view that the disease is predominantly sexually transmitted) is wrong for many reasons that have been made clear, in particular, by our lack of success in significantly slowing the pace of transmission. It's time to look at HIV as being part of health as a whole, as being related to the totality of conditions in which people live and work.
If we continue to fail to ensure good health services, education, nutrition levels, food security, infrastructure and numerous other conditions, all diseases, including HIV, will continue to spread. This will reduce people's quality of life and life expectancy. Self serving reports that show how well some favoured indicator is doing should be seen for what they are. Billions of people still suffer from and die from preventable and treatable diseases every year. That's nothing to celebrate.
(For further discussion of PrEP, see my other blog, pre-exposureprophylaxis.blogspot.com)
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