Fig. 6

Impact of annual mass drug administration (MDA) alone at 80 % coverage on the model-predicted community-level microfilariae (mf), third-stage larvae (L3) and circulating filarial antigen (CFA) prevalences of lymphatic filariasis (LF) for the five study sites that provided both mf and CFA baseline age data. The intervention simulations were carried out with the best model parameters obtained by joint fitting to both CFA and mf baseline data. The horizontal dashed line in each plot represents the model-derived extinction threshold signifying 95 % probability of elimination for the respective state variables, whereas the vertical dashed line denotes the time-point since the start of mass treatment at which the modelled prevalences had reduced/crossed below their respective 95 %-EP threshold values for all the best parameter vectors in the case of mf and L3 prevalences; beyond this time-point model runs were carried out without the effect of drug treatments as in Figs. 4 and 5. Note that for CFA, thresholds were crossed only much after 30 years (data not shown)