Presenting a study of the infection rate among pregnant women at a major international Aids conference in South Africa this week, Dr Michael Silverman said the prevalence of the virus that caused Aids fell from 23 percent in 2001 to 11 percent at the end of 2008. His study was based on tests of 18 746 women at a prenatal clinic where he works in rural Zimbabwe.
Silverman concluded that “a lot of the effect (of the decline in HIV infections) is from the collapsing economy”.
“You can’t pay the sex worker if you have no currency,” he said. “Because of the economic collapse, people are forced to stay home, like being in quarantine.”
Getting accurate Aids numbers in Africa, however, has been difficult, since researchers are often forced to guess from imperfect indicators, instead of counting actual numbers of HIV patients.
Researchers long have speculated how much they could drive down the incidence of Aids if people were constricted to having sex with partners in their age group. Now, in Zimbabwe, said David Katzenstein, a professor of infectious diseases at California’s Stanford University who has worked in Zimbabwe for 25 years, “everybody’s hungry, there aren’t as many sugar daddies and those that are around don’t have as much sugar.
“The good news from Zimbabwe is that there does seem to be a declining incidence in young women and maybe young men,” said Katzenstein, who was not involved with Silverman’s study.
Katzenstein noted there was no evidence of a decline in infection rates in other places which had incidences as high as Zimbabwe – Swaziland, Botswana and South Africa.
But Mike Chirenje, an Aids researcher in charge of obstetrics and gynaecology at the University of Zimbabwe, said: “You’re also talking about a period of time when a lot of people were not accessing ARV (antiretroviral) therapy. So you cannot rule out cases of people dying for lack of access to ARVs.”
Many ask how anyone can really know what is going on in Zimbabwe, where President Robert Mugabe’s fight to remain in political power triggered economic and social crises that caused as much as a third of the population to flee and collapsed government health and education.
The decline registered by Silverman is “in keeping with national data that shows from research 10 years ago a decrease from 30 percent (prevalence) to 15 percent today”, said Chirenje, who has done clinical trials, especially in HIV prevention and risk reduction through condom use.
Simon Gregson, a professor at Imperial College London and a demographer and epidemiologist who has worked half-time in Zimbabwe since 1998, said he also saw a sharp decline in Zimbabwe. He was not involved with Silverman’s study.
Gregson said: “We have found that people have been changing their behaviour and adopting safe practices.”
The studies showed people were having fewer partners, and condom use was quite high, Gregson said.
Chirenje also said studies from his research unit at primary health care centres had women reporting no changes in the frequency of their sexual activity of three or four times a week.
Pretoria NewsPost published in: News