Fig. 4.

Probability of elimination determined fifteen years after cessation of a five-year MDA programme dependent on annual movement rate during and after MDA. The probability of elimination depends on the percentage of the population moving between villages and the STH prevalence in the source village. The probability estimate is based on the percentage of simulations out of 300 iterations in which STH infections have gone extinct in the treated village. The solid line is the mean of ten sets of 300 iterative simulation runs. The shaded area is one standard deviation above and below the mean value. a, b The whole community receives MDA once a year with 75% coverage across all age groups. c, d The whole community receives MDA twice a year with 75% coverage across all age groups. a, c Results for A. lumbricoides. b, d Results for hookworm. Population size per village n = 500. Prevalence levels: low: < 20%; medium: 25–30%; high 60–70%