Figure 4.

Estimated sizes of 4 key hidden populations at risk of human immunodeficiency virus infection, Rwanda, 2011. Estimates are shown for the acquaintance network definition of a social tie (squares); the meal network definition of a social tie (triangles); and both the acquaintance and meal definitions blended together (diamonds). Earlier estimates for Rwanda from a capture-recapture study of female sex workers (gray circle) (45), a mapping study of female sex workers (black circle) (3), and an enumeration study of female sex workers (open circle overlapping gray circle) (46), as well as a direct estimate of male clients of female sex workers (X) (3), are also shown.