Almost 16% of people in the province are infected with the virus, up from 11.7% in 2002. The country's second-worst-hit area, the Eastern Cape, has a 9% prevalence rate, up from 6.6%.

KwaZulu-Natal also has the highest rate of HIV-infected pregnant women in the country - and possibly the world.

The Department of Health's new perinatal survey shows that in 2008 the provincial HIV rate among pregnant women in the 15-49 years age group stood at 38.7%, compared with an overall national rate of 29.3%.

One of the worst-hit areas is the uMgungundlovu area in the KwaZulu-Natal midlands, where the infection rate is 45.7%.

Professor Anna Coutsoudis, based at the University of KwaZulu-Natal's Department of Paediatrics and Child Health, said the high provincial infection rate among pregnant women could be linked to short-term relationships with multiple partners.

"The high levels of rape and violence against women in KZN further contributes to the HIV prevalence. Women are often not empowered to make a stand against these practices that fuel the spread of HIV."

She said intervention programmes were not working.

"Many interventions focus on the treatment of HIV/Aids, which is needed, while few encourage a change in lifestyle that will lead to a decrease in risk-taking behaviour," she said.

Nozuko Majola, director of operations at the Aids Foundation of South Africa, said: "KZN bears the highest burden of diseases associated with underdevelopment and poverty - TB is the leading cause of death in the province after HIV and Aids-related illnesses.

"A further challenge which KZN faces is the youthfulness of the province, as 70% of the population is under 35 years."

Professor Salim Abdul Karim, director of the Centre for the Aids Programme of Research in South Africa, said the province was not winning the war - but "with the new government, they are taking the kind of approach, which I think has a chance for success. They are saying, Let's first understand what we are dealing with, then let's work out what are the key things we need to do to beat this virus."

Professor Jerry Coovadia of the University of the Witwatersrand's Reproductive Health and HIV Research Unit in Durban said: "The provincial government has become much more active and is really trying to boost its energy to deal with the crisis."