The statistics were announced at the launch of a national HIV/Aids programme for sex workers in Johannesburg on Monday.
Transmission involves sex
"How can you talk about HIV prevention and not talk about sex work, knowing HIV transmission involves sex?" Sanac CEO Fareed Abdullah was quoted as saying at the launch.
Sex workers, their "non-commercial partners" and their clients accounted for between six and 11% of all new infections in South Africa.
Read: Porn actors must wear condoms, court rules
These "concerning" figures pushed Sanac and its partners to develop a programme aimed at fighting HIV/Aids in the sex worker industry, the publication reported.
"The programme also aimed at ensuring access to state social and health services where sex workers can receive HIV counselling and testing, treatment and contraception," Abdullah said.
Read: Rushing to put on condoms may lead to STIs
National co-ordinater of sex workers' movement Sisonke, Kholi Buthelezi, said it was the duty of all sex workers to ensure the programme was successful.
Clients refuse condoms
"We want to use condoms but sometimes our clients refuse," she said.
Men on new HIV preventative drug ditching condoms
Birth control shot may boost HIV risk
New test can identify both HIV and hepatitis
Image: Woman taking money from Shutterstock.