Fig. 7.

Risk of recrudescence of LF in communities as a result of the stopping of mass treatment following the WHO-recommended threshold of 1 % community-level microfilariae (mf) prevalence. Results shown in gray are for the LF intervention scenario when mass treatments (annual MDAs at 80 % coverage with no supplemental vector control) were stopped after the overall modelled mf prevalences crossed below the WHO-recommended threshold of 1 % (shown by solid horizontal line) in each site, whereas in the case of green curves, mass treatments were stopped after the modelled prevalences had reduced below the model-derived 95 %-EP thresholds (depicted by dashed horizontal line, for values cf. Table 2) in a site. Note that MDA stopping times for these thresholds varied within each site, with the vertical dotted line denoting the time-point when all model runs in a site had crossed the 95 %-EP threshold estimated for that site. Note that when modelled prevalences cross the 95 % EP in a site, all further simulated prevalences decayed steadily to the 0 state attractor, as predicted by theory [7]. The recrudescence probabilities (calculated as the percentage of the total model runs in which the mf prevalence rose above the 1 % threshold by the end of the simulation period) are provided in parentheses beside the names of the study sites