Figures from the South African health ministry suggest that the country's HIV epidemic may have levelled off, with a quarter of the adult population infected with the virus.
However, a leading South African AIDS expert, Dr. Salim Abdool Karim, deputy vice chancellor for research at the University of Natal, says that increased numbers of AIDS deaths may be reducing the apparent prevalence and masking increased rates of new infections.
The estimate is based on an annual survey of HIV prevalence rates of pregnant women attending state ante-natal clinics. Epidemiologist estimate that 4.74 million South Africans out of a total population of 44 million are infected with HIV, the highest number of adults in any country in the world.
The levelling off of the adult prevalence rate is attributed to a fall in the numbers of younger pregnant women testing positive for HIV. Last year 15.4% of pregnant women under 20 were found to be HIV-positive, a fall from 16.1% the year before.
Amongst pregnant women aged 20 to 24, the prevalence rate fell from 29.1% to 28.4%. The health ministry is attributing these improvements to HIV education programmes targeted at the young.
However, at the same time, the prevalence of HIV amongst pregnant women in their 30s has increased, off-setting the decline in the younger population.
Overall the health ministry statistics show that 24.8% of pregnant women are HIV-positive, compared to 24.5% last year. The percentage differences are not considered by the health ministry to be statistically significant.
Although epidemiologists have welcomed the apparent levelling off of new infections, officials at the World Health Organisation have pointed out that 25% adult prevalence of HIV is very high and may represent a natural plateau for infections.