Estimating the elimination feasibility in the 'end game' of control efforts for parasites subjected to regular mass drug administration: Methods and their application to schistosomiasis
Fig 4
Influence of PDD on key model outputs estimated with prevalence.
(a) Prevalence profiles derived from the PDD model (black line) and PDD-free model (red line) during 20 rounds of simulated annual MDA followed by 40 years with no intervention (the prevalence trajectory from the PDD-free model is shifted two months along the axis to improve clarity). In the presence of PDD, prevalence remains at 0% even after releasing MDA (a), while a lack of PDD allows the prevalence to rebound back to pre-MDA levels once MDA stops. (b) Mean prevalence-based BBR values of 100 model runs across 20 annual treatment rounds with error bars indicating standard deviation. (c) The prevalence-based elimination feasibility coefficient, ε, for the PDD model (black bars) and the PDD-free model (red bars) across each round of MDA. Error bars represent standard deviation and the dashed line between years 7 and 8 indicates the timepoint at which ε becomes significantly (p<<0) negative.