The prevalence of HIV/AIDS in South Africa is rising due to the world's fastest growth in new infections and a higher patient survival rate, according to a new health study

An estimated 12.2% of South Africa's population was infected with the HIV virus in 2012, compared with 10.6% in 2008, according to a survey of 38,000 people carried out by the country's Human Sciences Research Council. The percentage rise was partly due to 400,000 new HIV cases in the year studied, the highest in the world, taking the total number of people infected in South Africa to 6.4 million. Young black African women were the worst affected, with 23.2% of females aged 15-49 infected, compared with 18.8% of men, the study showed. Treatment of the virus is increasing, with around 2 million people on an expanded antiretroviral treatment plan. However, the study found the overall knowledge about how HIV is transmitted and can be prevented fell to 26.8% in 2012, from 30.3% in 2008. Three-quarters of those surveyed believed that they were at low risk of contracting HIV, even though one-in-ten of those tested were found to be already infected. South Africans under fifty were having increasing numbers of sexual partners and using condoms less. "The increases in some risky sexual behaviors are disappointing, as this partly accounts for why there are so many new infections still occurring," said Professor Leickness Simbayi, an investigator on the study. Despite a government push to spread the treatment of HIV, medical charities warned that that many clinics were running short of life-saving HIV/AIDs drugs.