Similarly, it is a truth long held self evident that a cultural proclivity for having several sexual relationships going at the same time is one reason some countries have bigger HIV epidemics than others.
If the studies presented today saying those theories aren’t necessarily so had been unveiled elsewhere, and a few years ago, they might have made bigger news than they did. But, as the author of one of the studies pointed out, “everyone here seems to have accepted that maybe behavioral interventions aren’t going to be effective, but biomedical ones will.” That was Steve Bellam of the University of Texas at Austin, Thursday, at his poster presentation titled “Transmission Rates and Not Sexual Contact Patterns Drive HIV Epidemic Intensity in Africa.”
Earlier in the day Guy Harling of the Harvard School of Public Health presented findings from a study titled “Age-Disparate Relationships and HIV Incidence Amongst Rural South Africa Women.” Looking at more than 2,400 women aged 15 to 49, the study found that age disparate relationships exist, but are not in themselves a risk for HIV acquisition or transmission. That goes for women under the age of 30, in relationships with men five years or more their senior. For women older than 30, relationships with similar disparities may even be protective, actually reducing their chances of getting HIV. Among the explanations: more mature men may tend to behave better. A factor that may have made a difference in the South Africa setting of this study, Harling said, was that in a poor setting with little money to go around, economic disparities that increase power differentials in age disparate relationships were less possible.
These conclusions “fly in the face of everything known,” a veteran journalist expostulated during a press conference after the presentation. That journalist, recently returned from one of many trips to southern Africa, wanted to know how rape, and extorted sex (the example: a teacher demanding sex in exchange for a grade) figured into these findings. Those situations were not defined by the women and girls whose information was gathered for the study as “relationships,” Harling replied. This brought it back to the photo of a billboard that Harling had opened his presentation with, typical of many erected across southern African towns and byways, warning: “Sugar Daddies destroy lives.”
“The big billboard campaigns may not help,” Harling said, mildly. Older women, he added, could even be misled by the campaigns.
Later that day, Bellan, a post-doctoral fellow with the Center for Computational Biology and Bioinformatics at the University of Texas at Austin, was met with less skepticism, but was kept busy explaining the charts and graphs on his poster showing how he reached his conclusion. He had set out to find an explanation for country level differences in epidemic prevalence, and used information from demographic health surveys from 25 African countries, on more than 40,000 couples. He found nothing to support the theory that multiple concurrent partnerships were more common in countries with larger epidemics. Multiple concurrent sexual partnerships do increase risks of HIV transmission, he said, “but it’s the wrong answer to the question of why some countries have bigger epidemics.” What he did find showed that countries with larger epidemics have faster transmission of HIV.
What, in turn, is driving that faster transmission is not clear, but Bellan leans toward biomedical factors, which could include circumcision, other prevalent infections, and genetic differences, including the CCR5-delta32 genetic mutation (the mutation that the donor for Timothy “the Berlin Patient” Brown’s stem cell transplant had) that is more common in America and Europe than Africa. He also does not think the differences are driven by sub-types of the virus. Of all the possibilities, he says, he hasn’t found a reason to pick a favorite.
But he adds, the study points to one conclusion, about campaigns telling people across Africa not to have concurrent partnerships: “That stuff hasn’t worked, this explains why.”