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Table 1 Description of model parameters and ranges used in the Latin hypercube parameter sets. All parameter values correspond to Schistosoma mansoni and Biomphalaria glabrata

From: Modeling schistosomiasis transmission: the importance of snail population structure

Parameter name Parameter description Parameter range References
m Maximum number of snails in the environment 5000–20,000 Estimated
c Liters of water in the environment 1000–100,000 Estimated
l2 Reduced rate of maturation in infected neonates/juveniles 0.714 of maturation rate in uninfected neonates/juveniles [35, 38]
l3 Averaged reduced rate of maturation in infected snails in the combined neonate/juvenile/small adult class 0.75 of maturation rate in uninfected snails [35, 38]
w1 Average time to mature from neonate to juvenile 7 weeks [35, 38, 51]
w2 Average time to mature from juvenile to small adult 5 weeks [35, 38, 51]
w3 Average time to mature from small adult to large adult 2 weeks [35, 38, 51]
1/dm Lifespan of miracidia 4–16 h [10]
1/dc Lifespan of cercariae 8–20 h [10]
u1 Mortality rate of uninfected neonatal snails 0.007–0.152/week [35, 36]
u2 Mortality rate of infected neonatal snails 0.062–0.607/week [35, 36]
u3 Mortality rate of uninfected juvenile snails 0.007–0.152/week [35, 36]
u4 Mortality rate of infected juvenile snails 0.062–0.607/week [35, 36]
u5 Mortality rate of uninfected small adult snails 0.007–0.152/week [35, 36]
u6 Mortality rate of infected small adult snails 0.062–0.607/week [35, 36]
u7 Mortality rate of uninfected large adult snails 0.007–0.152/week [35, 36]
u8 Mortality rate of infected large adult snails 0.062–0.607/week [35, 36]
1/u9 Lifespan of humans 60 years [48]
f1 Fecundity of susceptible small adult snails 40/week [26, 29, 30, 46, 49]
f2 Fecundity of exposed small adult snails 4.77/week [5, 29, 46, 49, 50]
f3 Fecundity of infected but not castrated snails 4.77/week [5, 29, 30, 46, 49, 50]
f4 Fecundity of susceptible large adult snails 40/week [5, 29, 30, 46, 49, 50]
f5 Fecundity of exposed large adult snails 4.77/week [5, 29, 30, 46, 49, 50]
f6 Fecundity of infected but not castrated adult snails 4.77/week [5, 29, 30, 46, 49, 50]
f7 Weighted average fecundity of susceptible snails in the combined neonatal/juvenile/small adult class 13.33/week [5, 29, 30, 46, 49, 50]
f8 Weighted average fecundity of exposed or infected but not castrated snails in the combined neonatal/juvenile/small adult class 1.59/week [5, 29, 30, 46, 49, 50]
g Castration rate of snails 0.1667/week [46]
1/y Prepatent period in snails 18–45 days [39]
e1 Exposure rate of neonatal snails to miracidia 50–150/week Estimated
e2 Exposure rate of juvenile snails to miracidia 50–150/week Estimated
e3 Exposure rate of small adult snails to miracidia 50–150/week Estimated
e4 Exposure rate of large adult snails to miracidia 50–150/week Estimated
p1 Per parasite susceptibility for neonatal snails 0–1 [5, 51, 52]
p2 Per parasite susceptibility for juvenile snails 0–1 [5, 51, 52]
p3 Per parasite susceptibility for small adult snails 0–1 [5, 51, 52]
p4 Per parasite susceptibility for large adult snails 0–1 [5, 51, 52]
s1 Shedding rate of neonatal snails 2800/week [29, 43]
s2 Shedding rate of juvenile snails 5500/week [29, 43]
s3 Shedding rate of small adult snails 6000/week [29, 43]
s4 Shedding rate of large adult snails 6800/week [29, 43]
s5 Averaged shedding rate in combined neonatal/juvenile snail class 3925/week [29, 43]
s6 Averaged shedding rate in combined small/large adult snail class 6774/week [29, 43]
s7 Averaged shedding rate in combined neonatal/juvenile/small adult snail class 4925/week [29, 43]
b Snail-to-human transmission rate 0.00001–0.001/week Estimated
hw Probability of eggs reaching water and hatching 0–1 [27, 39, 51]
q1 Recovery rate among lightly infected humans 0.2–0.333/year [39]
q2 Recovery rate among moderately infected humans 0.2–0.333/year [39]
q3 Recovery rate among heavily infected humans 0.2–0.333/year [39]
1/lh Latent period in humans 25–30 days [39]
v1 Proportion of infected humans who are lightly infected 0–1 Estimated
v2 Proportion of infected humans who are moderately infected 0–1 Estimated
v3 Proportion of infected humans who are heavily infected 0–1 Estimated
g1 Eggs produced by a lightly infected human 7000/week [39, 53]
g2 Eggs produced by a moderately infected human 28000/week [39, 53]
g3 Eggs produced by a heavily infected human 70000/week [39, 53]
g4 Eggs produced per mated female schistosome 350 /day [54]
i Grams of feces produced per human 200/day [55]
Nh Total human population size 200 Estimated
z Scaling parameter 1–10 Estimated
k Worm aggregation constant 0.24 [51]