Fig 2. Model-predicted trend in mf-prevalence in the population aged 5 years and above and Ov16 antibody prevalence in children aged 0–9 years in relation to the duration of annual mass drug administration, assuming a fixed coverage of 70%.

Average of 1,000 simulations (minus failed runs) per scenario. Results are shown for transmission settings with moderate and high transmission (ABR 10,150 and 18,078; average pre-control CMFL 10 and 55 mf/skin snip, respectively) and for different treatment coverage levels. The Ov16 antibody prevalence was estimated assuming that the Ov16 antibody test has a sensitivity of 80%, and specificity of 99%. Results are shown for each of three hypotheses regarding the seroconversion trigger, with the Ov16 antibody test becoming positive as soon as the first male or female worm establishes in the human body, before it matures (hypothesis 1); idem, but after maturation (hypothesis 2); or after the start of mf production (hypothesis 3).