One in every 18 street-based women sex workers of all ages in South Africa is estimated to be infected with HIV within a year.
This is according to a consortium of investigators from six institutions, including Wits University, University of Cape Town, African Potential Consulting, Stellenbosch University, SA Medical Research Council and the National Institute for Communicable Diseases.
The investigators have published a new analysis of data obtained from the first national survey of women sex workers in the country.
The paper was published in the Lancet HIV Journal on Wednesday.
A total of 3 005 women sex workers were interviewed between February 4 and June 26 2019, of which 62% tested HIV positive and 48% reported client sexual violence in the previous year.
Women are disproportionately affected by HIV in South Africa and of the 7.3 million adults living with HIV, 64% are women.
A national study of women sex workers reported a prevalence of 62%.
Women sex work contributes greatly to transmission dynamics in HIV epidemics in sub-Saharan Africa. The high risk of HIV for women sex workers should be understood within the context of economic hardship, violence and criminalisation of the profession,” read the report.
Dr Jenny Coetzee, the principal investigator of the woman sex worker study at Wits University’s Perinatal HIV Research Unit and African Potential Consulting, said their survey had many aims.
Coetzee said they had previously written about designing the study of women sex workers, HIV prevalence and the HIV cascade of care, experience of violence, mental health and access to health care, particularly treatment for HIV and pre-exposure prophylaxis services.
“This level of risk is despite broad gains in HIV programmes targeting the population and offering access to pre-exposure prophylaxis and rapid antiretroviral therapy initiation, emphasising the need to strengthen efforts across age groups. Clients of sex workers not only present the primary risk of infection to women sex workers, but also bridge to the general population, and no programmes exist to target this key population in South Africa,” she said.
Dr Reshma Kassanjee of the University of Cape Town’s Centre for Infectious Diseases Epidemiology and Research and the chief analyst and lead author of the paper, said ideally, to measure infection rates, one would recruit people who are initially not infected, and then test them repeatedly and note how rapidly infections occur in this cohort.
“One indirect way of extracting the same information at a single time would be to find out when people most recently tested negative for HIV, and then see which and how many of these people now test positive. Interestingly, the estimate we obtained using this approach was much higher than the three mutually overlapping estimates we obtained from the three other methods of estimation we used. This inflation in the estimate is consistent with a possible social desirability bias in the reporting of recent previous negative tests.”
Dr Coetzee explained: “We reached our study subjects via various programmes that provide women sex workers with various forms of support, including messaging about the importance of frequent testing.”
Kassanjee added considering the range of estimates from different approaches, they concluded that among 100 initially uninfected women sex workers, they expected between four and seven to become infected over a year, with uncertainty around these estimates and a clear need to continue and strengthen epidemiological surveillance in this group to support future incidence estimations.