The impact of the socio-economic factor of poverty on the distribution of lymphatic filariasis (LF) infection and extinction thresholds. a Prevalence of LF Mf prevalence is disproportionately aggregated in the poor (p < 0.05). Data for Mambrui from Wijers and Kinyanjui ; and for Philippines from Grove et al. . b The typical distribution of LF infection in a community. Estimation of the aggregation parameter k from the observed Mf count data indicates a highly over-dispersed/heterogeneous distribution and transmission of LF-mf in individuals of Masaika in Tanzania (data summarized in ; methods for estimating k and deriving the negative binomial frequency distribution are as given in [70, 71]). c Elimination thresholds for LF prevalence can vanish under heterogeneous/aggregated transmission conditions (ie. for low k values: solid line) compared to more homogenous transmission settings (with higher k values: dashed line). Methods used to estimate the transmission thresholds shown in the fig. as a function of k are as detailed in Singh et al.