Tuesday, January 11, 2011

Flawed HIV Transmission Models Beget Flawed Strategies

A researcher called Jeremy R Magruder has written an interesting thesis about 'marital shopping' or 'spousal search' patterns being behind high and medium prevalence HIV epidemics in African countries. According to his model, when people are searching for a partner, they have unprotected sex with several different people in a relatively short space of time.

The factor that really increases the probability of HIV transmission is that people who have recently been infected are most infectious. Their HIV positive status may not even be detected by tests, so regular testing would be unlikely to help much. Therefore, this brief period of rapid partner change is likely to result in more transmissions than other scenarios.

This model is interesting because Magruder suggests that advising people to use condoms for the first three months of a new relationship could provide very high levels of protection. Better still, evidence has suggested that people respond better to behavior change strategies that are more feasible.

Unsurprisingly, being told to abstain for an indefinite period, even if it is until marriage, is a lot less feasible than abstaining until the end of secondary school. And using condoms for a few months into a new relationship is a lot more feasible than using condoms, not just until marriage, but throughout marriage.

Magruder also notes that efforts to reduce sexually transmitted infection prevalence and male circumcision are unlikely to have much effect on transmission rates. He even dismisses the benefits of looking at antiretroviral treatment as prevention, something some technology fanatics have suggested as their magic bullet of choice.

But the model becomes less credible when you start to ask why prevalence in some African countries is only 1%, in others it is over 5% and in the worst affected countries it is over 25%. Prevalence is over 40% in some demographic groups and many people who never have sex, or who always use protection, are also infected.

Within countries, prevalence also varies greatly, with less than 1% in some areas and figures that are 10 or 20 times higher in other areas. Variation between tribes can be equally high and the ratio of male to females in some tribes range from 17% to 120%. Could this really be explained by differences in spousal search patterns?

Magruder could explain these differences by reference to differences in levels of 'unsafe' sexual practices or in levels of protective behavior. But this is one of the great mysteries of sexually transmitted HIV: transmission rates can be higher among those who practice 'safe' sex. Attested levels of safe and unsafe sexual practices don't correlate with HIV prevalence.

Also, is Magruder suggesting that spousal search patterns changed some time in the 1970s and 1980s, a phenomenon which might explain why the virus was spread so rapidly during this period and not before? And is he suggesting that this search pattern changed again some time in the 1990s, when HIV incidence, the yearly rate of new HIV infections, peaked and declined in most African countries?

Magruder has assumed the truth of a version of the behavioral paradigm, the view that HIV is almost always transmitted sexually. He simply ignores the possibility that some, perhaps a lot of HIV, is transmitted non-sexually.

But Magruder doesn't subscribe to the view that African people engage in inordinate amounts of sex with little concern for the consequences for themselves or their families. And that is refreshing. But it may not help him gain acceptance for his thesis. The HIV orthodoxy is very committed to its racist and sexist views of HIV transmission.

Magruder may have shed some light on how sexually transmitted HIV could be spread by people who are only human and can only engage in humanly possible levels of sexual behavior. But until some light is also shed on what proportion of HIV is transmitted sexually and what proportion is transmitted non-sexually, his strategy will bring only limited benefits.



Paddy O'Gorman said...

Thanks Simon, your blogs are a breath of fresh air with robust common sense on the alleged sexual hyper-activity of Africans.

These quack racist assumptions have an effect outside Africa too. Just recently I was working at a Dublin taxi rank where black drivers are getting a hard time. Irish women believe Africans might rape them.

And you can't blame Irish women for being influenced by all they are being told by Aids activists. I've been trying for over a decade to challenge Dr Michael Meegan of ICROSS who claims "African have far more sex than anyone else" (i/v with Irish Times at Durban Aids conference). Likewise with the Rose Project who claim that child rape is driving Aids in Kenya, as if child rape was unknown in Ireland! These groups ignore my questions, safe in the knowledge that the media, showbiz, medical and political establishments will always make any questioning of Aids orthodoxy taboo.

Meanwhile in Ireland, as Aids remains concentrated in risk groups, STIs in general have gone up four-fold in a decade (hpsc.ie for stats.) And we Irish have the nerve to lecture Africans on their sexual behaviour!

Paddy O'Gorman

Simon said...

Hi Paddy, thanks for your comments. You're right, even professionals who should be able to analyze racist, pseudo-intellectual claptrap for what it is seem to accept this rubbish about Africans, though it's been doing the rounds for decades.

Meegan is not a doctor and whatever he writes or speechifies is lifted from journalistic ramblings, I don't know why anyone even bothers to challenge him. They would be better off challenging his financial and sexual dealings than flattering his academic pretensions.

As for child rape, you're right, it occurs everywhere and even that doesn't actually account for high rates of HIV transmission. But as you've found, challenging the orthodoxy doesn't make you any friends.

I hope you continue to challenge what people seem to accept without question about Aids and sexuality in Africa. What you say about STIs holds for the US and other Western countries as well.

There's a lot about Meegan here, if you haven't already seen it:


He has quite a rarefied view of Kenya, despite the amount of time he claims to have spent there. He has not done any research himself, he doesn't even visit any of the places he claims his organization works in. Hardly anyone knows him there, except by 'reputation'. I've asked around.

But as for his expertise in African affairs, sexuality, languages, or anything else he claims, he knows diddly squat.


Paddy O'Gorman said...

Astonishing stuff on Meegan.I have watched that man collecting plaudits from all quarters. As soon as Meegan made his quack contribution to the Durban conference, his views were immediately endorsed by Senator Doctor Mary Henry in a letter to the Irish Times. He has received awards from Royal College of Surgeons, he was Eircom Person of the Year, he has had celebrities such as Elton John and Lorraine Keane support him (why are celebs so fascinated by Aids?), Dr Garrett Fitzgerald has endorsed him and, most shamefully of all, he has had no end of uncritical media comment, including a hagiographical TV documentary in which he was once again given a platform to denounce the sexual behaviour of Africans.

All Meegan's sycophants may well now desert him, but I want them to re-examine his quack racist claims that they were so keen to endorse. He may be gone (I hope so) but the damage he has done lives on.

Paddy O'Gorman

Simon said...

Thanks Paddy,
The guy has bullshit coming out of his pores. I don't know why anyone listens to him. But it's just stuff he lifts from the mainstream press, I've never heard of anything he has said that is in any way original. I guess you can't do that much research in a bar or a gym.

What is most disgusting is that genuine academics also subscribe to the racist stuff that seems to be accepted by the HIV orthodoxy. There has never been adequate research into varying sexual behavior around the world that could answer questions about sexual transmission of HIV. It seems amazing, after all these years and given the level of obsession.

It's also disturbing that Africans also seem to accept the view that they engage in sex far more than most people would think possible. Never mind about Meegan, the media or the academic orthodoxy, people need to know what risks they face so that they can take steps to avoid them. Otherwise, all the money poured into HIV prevention is being wasted.

I find it hard to believe that this is allowed to happen, that people are so duped and that, as a result, they unnecessarily risk illness and death for themselves and possibly their children.