The findings suggest an urgent need to scale up access to quality HIV prevention programs in these countries.
"Although female sex workers have long been understood to be a key affected population, the scope and breadth of their disproportionate risk for HIV infection had not been systematically documented," said Stefan Baral, MD, MPH, MBA, lead author of the study and associate director of the Johns Hopkins Bloomberg School's Centre for Public Health and Human Rights.
"In addition to antiretroviral treatment and ongoing HIV prevention for sex workers, considerations of the legal and policy environments in which sex workers operate, and the important role of stigma, discrimination, and violence targeting female sex workers globally will be required to reduce the disproportionate disease burden among these women," Baral stated.
For the study, Johns Hopkins researchers conducted a meta-analysis of 102 previous published studies representing almost 100,000 female sex workers in 50 countries.
Overall, HIV prevalence in female sex workers in low- and middle-income countries was found to be about 12 percent, which equated to an increased risk of infection for sex workers 14 times that of other women in these countries.
In 26 countries where background levels of HIV were considered "medium" to "high," approximately 31 percent of the female sex workers were found to have HIV and were 12 times more likely to be infected compared with women from the general population.
Sex workers in Asia had a 29 percent increased risk for HIV infection compared to other women, which was the greatest disparity among the regions studied. Sex workers in Africa and Latin America were 12 times increased risk compared to other women in these regions.
The study was published online in The Lancet Infectious Diseases.