HIV infection is on the rise in South Africa, and women continue to be most affected, the Human Sciences Research Council (HSRC) said on Wednesday.

In a new study, published in the March issue of the South African Medical Research Journal, which examined an unparalleled number of 15,851 blood specimens to assess national HIV incidence, the HSRC found that around 571,000 people had been newly infected with HIV in 2005 - about 1,500 new infections per day.

"The findings are certainly alarming, but even more worrying is that women and young adults continue to be the most affected," Dr Victoria Pillay, an HSRC research specialist and one of the study's authors, told IRIN-PlusNews.

HIV incidence among women aged 20 to 29 was a high 5.6 percent - six times more than men in the same age group, while women and young girls aged 15 to 24 accounted for 90 percent of all recent infections.

"There is a sense that current prevention campaigns are not yielding the expected results, especially among our female population," Pillay warned.

She attributed the incidence of HIV among women to the wide spectrum of socio-cultural attitudes, which were usually more prevalent in informal urban and rural settings.

According to the research article, people in urban informal settlements had the highest incidence (5.1 percent), followed by those in rural informal areas (1.6 percent) and urban formal areas (0.8 percent).

Pregnancy was also highlighted as a main risk factor in HIV infection: among women and young girls aged between 15 and 49, 5.2 percent of pregnant respondents were newly infected, compared to 3.7 percent of non-pregnant women.

"Current approaches need a rethink. There is also a great urgency for the presence of men as partners in curbing the impact of the disease on women and young girls," Pillay said.

Sharing her sentiments, officials at Sonke Gender Justice (SGJ), a local HIV/AIDS, gender and human rights nongovernmental organisation, said a patriarchal social culture was also to blame.

"Men continue to rule the roost and, as a result of age-old imbalances in power between the sexes, women are often left with little room to negotiate safer sex," SGJ co-director Bafana Khumalo commented.

Khumalo welcomed the new findings as a timely guide, saying the government planned to strengthen its anti-AIDS efforts and officials were finalising a draft of the 'National Strategic Plan on HIV/AIDS and Sexually Transmitted Infections for 2007 to 2011', which aimed to halve the rate of new HIV infections by 2011, particularly in the 15 to 24 age group.