Figure 6.

Extinction and re-emergence of infection following six rounds of mass drug administration. The effect of six annual mass drug administration (MDA) rounds on 500 accepted or passing parameter sets of the model fitted to baseline age-mf prevalence data of the Papua New Guinea village, Ngahmbule. The figure on the left (a) shows that the response to six MDAs is very similar in each realization, with the prevalence dropping to very low levels after the final treatment round. The figure on the right (b) zooms in on the region encircled by the light blue line; it shows that, following six treatments, only approximately half of the 500 trajectories are sufficiently reduced in mf prevalence to have dropped below the breakpoint and for the parasite to go to extinction.