As large as national and regional HIV prevalence differentials are, the country differences in HIV prevalence in female populations are even greater and are thousands of times higher in Swaziland compared to most low HIV prevalence countries as shown in this table. The female to male ration in sub-Saharan Africa (SSA) where extensive (not generalized) heterosexual HIV transmission predominates has been consistently about 1.2 to 1. In all other HIV epidemics where the predominant risk behaviors are in MSM and IDU, the male to female ratio of HIV infections is usually more than 5 to 1!

Sub-Saharan Africa has close to 70% of all global HIV infections and close to 90% of pediatric AIDS and AIDS orphans. In SSA and the Caribbean where heterosexual HIV transmission predominates, over 50% of all infections are in females, in the rest of the world females represent only a little over a quarter of all infections because of MSM and IDU epidemics.