Wednesday, August 4, 2010

Do We Want to Reduce HIV Transmission or Not?

Considerable resources have gone into HIV 'prevention' programs over the last few decades. Billions of dollars have been spent on labor and materials and millions of people have been involved in one way or another. But most of these programs, when they have been carefully evaluated, have been found wanting in numerous ways. And careful evaluation is itself both expensive and time consuming. After so many years of lack of success, or failure, depending on your perspective, you might expect the less good prevention programs to have been phased out and replaced with more viable ones.

A careful re-evaluation of the MEMA kwa Vijana program in Tanzania by Aoife Doyle, et al, published in June in PLoS Medicine, looks at a school based prevention program that was started in 1999 and subsequently found to give little benefit. It was argued that the original evaluation was too soon after the intervention took place and that, over time, the program would have more benefit. The re-evaluation showed that it was not just a matter or time or volume and that nine years after the program started, it was still not having much impact on either primary (HIV rates, herpes simplex rates and unplanned pregnancies) or secondary outcomes (other sexually transmitted infections).

The study concluded that the "results of this trial show that such skills-based sexual health education interventions and youth friendly health services can make a valuable contribution towards the...goal of increasing young people’s access to the information, skills, and services they need to reduce their vulnerability to HIV. However, these results imply that such interventions, on their own, will not be sufficient to reduce HIV and other STIs among young people in sub-Saharan Africa."

The MEMA kwa Vijana program did show some improvement in knowledge, attitudes and even some change in sexual behaviors among those exposed to the intervention. But the difference between those who had been exposed and those who hadn't been exposed was small, certainly too small to be expected to reduce HIV, herpes simplex or unplanned pregnancies significantly. The results of the many years of trying to reduce HIV transmission could be called good, but they are seriously limited. It is, indeed, a good thing if young people know more about sex, risk and limiting risk. But why years of expensive intervention and research are needed to make clear something that is already widely acknowledged is what makes this approach to HIV so exasperating.

Most HIV prevention interventions carried out in African countries are based on the assumption that HIV is transmitted, almost exclusively, through heterosexual sex. In the words of the Editor's Summary at the end of this paper, "HIV is most often spread through unprotected sex with an infected partner, so individuals can reduce their risk of HIV infection by abstaining from sex, by delaying first sex, by having few partners, and by always using a condom."

This is sometimes called the 'behavioral paradigm' and it leads to the further assumption that in order to reduce HIV transmission, all that is required is to teach people about sexual risks and how to minimize them. Children (and adults) are bombarded with 'information' about HIV, STIs, pregnancy and various 'behaviors' that are risky. They are further bombarded with words such as 'abstinence' and 'being faithful', these being assumed to be ways of minimizing risks. Less frequently, they may hear about or even receive condoms, often after being told that these do not give much protection. But the words 'abstinence' and 'being faithful' have been demonstrated to have little meaning for most people. And they are sometimes bandied about in the absence of the word 'sex' or any discussion of what sex is, safe or otherwise.

Participants in MEMA kwa Vijana may have reduced their numbers of partners, increased their use of condoms and answered various questions they were asked. But if the intervention didn't affect the number of pregnancies or levels of HIV, herpes or other STI transmission, knowing about safe and unsafe sex is not the same as practicing safe and avoiding unsafe sex. Knowledge does not necessarily have much affect on behavior. There's nothing surprising about this, except the apparently long held hope that, one day, 'correct' knowledge and 'appropriate' attitudes will give rise to appropriate behaviour; specifically, later sexual debut, fewer lifetime partners, greater condom use, etc.

Doesn't this and other experiments carried out on relatively deprived, undereducated and unhealthy people indicate that 'unsafe' sexual behavior may not be behind all HIV transmission? And if sexual behavior is the problem, we haven't identified what it is about sexual behavior in some parts of some African countries that gives rise to rates of HIV transmission tens or even hundreds of times higher than in non-African countries with similar sexual behaviors.

The overall results of the program in question were poor. But they were far poorer for females than for males, both in terms of behavior change and outcomes. The re-evaluation finds that those who were exposed to more of the program received greater benefit, which may give some slight comfort. But those likely to have least exposure to a school based program in many high HIV prevalence areas would be females. Girls are often not sent to school for very long and are likely to miss more days and perform less well in exams. Yet, females are more likely to become infected with HIV and other STIs and they are more likely to be infected early on in life.

If HIV transmission is not all about sex then concentrating almost exclusively on prevention of sexual transmission is not likely to have optimum impact on HIV transmission. Male circumcision and microbicides will only reduce sexually transmitted HIV, at best. And these and other programs tend to target those thought to be most vulnerable to sexual risk. Pre-Exposure Prophylaxis, the use of oral antiretroviral drugs to prevent HIV, may also reduce non-sexual HIV transmission. But this also is currently being targeted at groups thought to be at high risk of sexual transmission. Which efforts, then, are going to reduce HIV transmission in the majority, who are at low risk sexually, and therefore unlikely to be targeted?

The report notes that "Qualitative work carried out in the trial communities in 1999–2002 found that many young people were not always in a position to use the knowledge and skills obtained through MEMA kwa Vijana. Peer pressure to be sexually active, and widespread attitudes and practices in the broader community such as negative attitudes to condoms, material exchange for sex, and older male–younger female relationships, may have posed too great a challenge for youth who wanted to reduce their risk behaviours."

So there are two major problems: rates of sexual transmission of HIV are unlikely to be influenced significantly by such programs; but non-sexual transmission of HIV will not be influence at all. It seems that young people are not being told anything about HIV transmission through unsafe medical or cosmetic practices. If they are not told that such a phenomena exist, they are not going to know how to protect themselves. Even if sexual HIV prevention programs don't work very well, for whatever reasons, prevention of non-sexual HIV should not be ignored. Currently, it is being ignored.

Indeed, years of monitoring and collecting data on thousands of young people in programs like this ignore the possibility that some, perhaps many of the people becoming infected, are infected by some mode other than through sex. Many years of intrusive research have been wasted because of the assumption that HIV is mostly transmitted sexually. Research into the MEMA kwa Vijana program may have been carried out with the best intentions. But assuming that the only risks that people face are sexual risks is unwarranted and dangerous. And the assumption is not due to ignorance on the part of those doing the research. Non-sexual risks of HIV transmission have been recognised for almost as long as sexual risks.

Sex education is, undoubtedly, a good thing. Reducing transmission of HIV and other STIs is a good thing, as is reducing unplanned pregnancy and many of the other projecte outcomes of good sex education. But there are educational prerequisites to the success of a sex education program. Children need to have a basic level of education to benefit, for a start. And they need to be attending school frequently enough to gain enough exposure. Teachers and peer educators need to be well trained and committed to the program. Basic school education is not guaranteed for most children in Tanzania, so the potential for a school based sex education program is probably seriously diminished.

It is widely known, even in the HIV industry, that HIV is not exclusively transmitted sexually, not even almost exclusively. Programs assuming the behavioral paradigm have all failed; this one in Tanzania is by no means the only one. These two facts put together should, one would think, lead the learned industry leaders to conclude that the behavioral paradigm should be discarded. They should see the need to modify programs that aim to reduce sexual transmission. And they should give some attention to assessing the non-sexual risks and design programs to reduce these risks and to teach people about them, rather than denying that they exist or that they are relevant.

Those evaluating the MEMA kwa Vijana program don't let on that they are aware that young people may face non-sexual risks or that some of those who became infected may not have been infected through unsafe medical or cosmetic procedures. The program may not have been the unmitigated waste of time that it appears. Some sexual transmission may have been avoided but the numbers infected didn’t reduce because some were infected by other means. But even if the program had better results than first appears, it is just as much of a waste of time because it does not increase awareness of non-sexual risks of HIV transmission.

There is little point in only informing people about one kind of risk, sexual risk, and neglecting all others. It would be of some slight value if sexual transmission had been reduced, but it probably wasn’t. And it is disappointing that this paper just adds to the deep pile of research that has come up with similar findings without coming to the conclusion that the problem is the behavioral paradigm, that HIV is not "most often spread through sex with an infected partner". If both wheels on your bike are punctured, putting extra patches on one wheel and none on the other is pointless, you will still be unable to cycle. For how long are such considerable resources going to be wasted while HIV transmission continues, almost unabated?


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