Study measures HIV rates among female sex workers

HIV was expected to be more common among women who work in prostitution than in other groups, but the rates had never been documented and remained estimates, especially in low- and middle-income countries. A new study has now given precise figures. Published in Lancet Infectious Diseases, it drew on more than a hundred earlier studies of about 100,000 female sex workers in fifty countries. It found that 12% of female sex workers in low- and middle-income countries have HIV; in other words, a sex worker in these countries is fourteen times more likely to have HIV than other women.

"We determined the HIV rate among female sex workers and found it far higher than among other women of reproductive age in low- and middle-income countries," says the study's author. "It was known that sex workers are most at risk, but the scale of that risk had not been documented before our study."

Rates varied between countries. In some countries where HIV is widespread, more than 31% of sex workers were infected. By continent, the risk was highest in Asia, where sex workers were about 29 times more likely to be infected than other women, and lower in Africa and Latin America, where they were 12 times more likely.

This means that in Asia the virus is concentrated among sex workers, while in Africa and Latin America it is spread more widely across society.

Thirty years after the AIDS epidemic began, it is clear that many sexual partners, together with the persecution, exploitation and violence sex workers face, poverty, poor health knowledge and limited access to care, make them likely carriers of HIV. But the study shows that their infection rates, and so the risk of passing it on, have reached alarming levels, and quick action to limit the spread is urgently needed.

"These results suggest an urgent need to help these women reach effective HIV programmes and services," the author says, "because the high rate of infection among sex workers means the virus could pass to a large number of the clients who visit them."