Table 1.

Model variables and parameters.

Symbol	Variable
$H_i^p$	abundance of people hosting p parasites in community i
S i	abundance of susceptible snails in community i
I i	abundance of infected snails in freshwater used by community i
C i	abundance of cercariae in freshwater used by community i
M i	abundance of miracidia in freshwater used by community i
μ H	baseline human mortality rate
K i	human population size in community i
${ℱ}_i=a{\sum }_{j=1}^n{Q}_{ij}{\theta }_j{C}_j$	force of infection for people in community i
a	probability of schistosome establishment in human hosts
Q = [Q ij]	human mobility matrix (between communities i and j)
θ i	rate of human exposure to cercariae in community i
γ p = pμ P	parasite resolution rate for human hosts with p parasites
μ P	schistosome mortality rate
${\alpha }_H^p=p{\alpha }_H$	schistosomiasis-related mortality rate for human hosts with p parasites
α H	additional human mortality rate induced by each parasite
P	maximum number of parasites in human hosts
T	parasite threshold for clinical infection in humans
μ S	baseline snail mortality rate
N i	snail population size in community i
b	rate of snail exposure to miracidia
α S	infection-related mortality rate in snails
π C	cercarial shedding rate by infected snails
μ C	mortality rate of cercariae
${\mathcal{G}}_i={\pi }_M{\delta }_i{\sum }_{j=1}^n{Q}_{ji}{\mathcal{W}}_j\mathrm{/2}$	rate of freshwater contamination by infected people in community i
π M	miracidial shedding rate by infected humans
δ i	probability of freshwater contamination by infected people in community i
${\mathcal{W}}_i={\sum }_{p=1}^{P}p{H}_i^p$	abundance of schistosomes carried by residents of community j
μ M	mortality rate of miracidia
${\beta }_i=a\frac{{\pi }_C}{{\mu }_C}{\theta }_i{N}_i={\beta }_0(1+\phi {\rho }_i{\omega }_i)$	synthetic human exposure rate
${\chi }_i=\frac{b}{2}\frac{{\pi }_M}{{\mu }_M}{\delta }_i={\chi }_0(1+\xi {\rho }_i{\omega }_i)$	synthetic human contamination rate
ρ i	rurality score of community i
ω i	freshwater availability score of community i
β 0	baseline value of the synthetic human exposure rate (calibrated)
χ 0	baseline value of the synthetic human contamination rate (calibrated)
ϕ	shape parameter for the human exposure rate (calibrated)
ξ	shape parameter for the human contamination rate (calibrated)

The top and middle parts of the table summarize the state variables and the parameters of the schistosomiasis transmission model described in the Methods section, while the bottom part describes the synthetic human exposure and contamination rates obtained after introducing equilibrium assumptions for larval abundances and rescaling the remaining state variables (see SI for details).