Sex workers performing internal vaginal washing as a means of HIV prevention are three times more likely to contract the virus than those who do not, a 10-year study in Africa has suggested.
According to researchers from the University of Washington, the practice, found to be prevalent among a third of the women in various clinical settings in sub-Saharan Africa, often stripped the vagina's natural protection against certain infections.
"This is the first prospective study to demonstrate a significant association between vaginal washing and HIV acquisition. A causal association between [the two] seems biologically plausible," lead author Dr Scott McClelland told the BBC.
However, McClelland and his team stressed that the cultural significance of the practice had to be understood before any interventions were recommended.
The research has been published in AIDS, the official journal of the International AIDS Society.