Fig. 2

Maximum likelihood estimator fits to worm expulsion data for Ascaris (Panel a data from Elkins et al.), Trichuris (Panel b data from Bundy et al.), and Hookworm (Panel c data from Bradley et al. – Necator americanus). The fits are performed for individual worm counts for Ascaris and Trichuris, and for mean counts for hookworm (in the absence of individual-level data)., The solid line is the mean individual worm burden as a function of age for the maximum likelihood parameter estimates and the dotted line is the 97.5 percentile for individual worm burden from the model, based on the assumed negative binomial distribution. The crosses are the raw data