Fig. 3
From: A potential transition from a concentrated to a generalized HIV epidemic: the case of Madagascar
R0 changes as a function of βY, the sexual encounter rate of males, and pY X, the transmission probability from infected females to males1. 1The rest of model parameters, but female-to-male transmission probabilities (pYX), and the male sexual encounter rate (βY), are kept constant. Their values are chosen to correspond to Antananarivo (see Additional file 1: Table SB1, and also Figs. SB1 and SB2). Time-dependent parameters Fx, FY, δX and δY are set to their values in 2000 (see Additional file 1 and Table SA1 for a full definition of model parameters). The estimated average female- to-male transmission probabilities and the sexual encounter rates (βY) are represented by a little circle defining the initial coordinates of the arrow. The tip of the arrow represents the potential reduction in R0 caused by a 60% reduction in the transmission probability from infectious females to males as a consequence of circumcision (as reported in [16,17,18])