AIDS is posing an increasing threat to women, especially in developing countries. According to the World Health Organization, AIDS is the leading cause of death and disease among women of reproductive age in low- and middle-income countries, particularly in Africa.

While in 1985 there were as many HIV-infected men as women in sub-Saharan Africa, women's infection rate has steadily increased and now the number of HIV-infected women is larger than HIV-infected men. To date, approximately three quarters of all women with HIV live in sub-Saharan Africa.

There are several reasons for this vulnerability. Women and girls are particularly susceptible to be infected due to biological, social, cultural and economic factors. The female genital tract has a greater exposed surface area than the male genital tract, making it more prone to infection with every exposure. Younger women may be even more vulnerable because they are more often victims of coercive or forced sexual relations with men who may already be infected.