The World Health Organization (WHO) is urging all sexually active gay men to take antiretroviral drugs to reduce the spread of HIV.
The organization says the move may help prevent a million new HIV infections over 10 years.
Studies indicate that women sex workers are 14 times more likely to have HIV than other women.
Men who have sex with men are 19 times more likely to have HIV than the general population.
Transgender women are almost 50 times more likely to have HIV than other adults.
For people who inject drugs, studies show the risks of HIV infection can be also 50 times higher than the general population.