Schematic representation of the disease model. Prevalence of troublesome itch was estimated based on a relationship with the prevalence of adult female worms, previously derived using the ONCHOSIM model[25, 26]. Incidence of blindness was estimated as a function of microfilarial load (lagged by two years) based on a log-linear Poisson model. The number of individuals with visual impairment was estimated using a published ratio between the prevalence of visual impairment and that of blindness. Excess mortality due to onchocerciasis was assumed to occur via mortality among individuals suffering onchocerciasis-related vision loss (blindness and visual impairment)[10, 48], plus an independent (from the former) risk of mortality among sighted individuals with high microfilarial load (lagged by two years)[8, 9]. Further descriptions are provided in the main text and Additional file1: Text S1.