Figure 1. Proportion of incidence contributed per individual from a household of size (solid line) and the probability distribution of a randomly chosen individual belonging to a household of that size, P(m), based on the negative binomial distribution in (A) The Gambia – the black lines correspond to Upper Saloum district and the red lines correspond to Jali village; and (B) Tanzania – the black lines correspond to Kahe Mpya sub-village and the red lines correspond to Maindi village.