Table 1. State variables used in the multi-group transmission models.

Variable	Description
Sh,1	Number of susceptible humans who seldom eat raw or uncooked fish
Ih,1	Number of infected humans who seldom eat raw or uncooked fish
Sh,2	Number of susceptible humans who moderately eat raw or uncooked fish
Ih,2	Number of infected humans who moderately eat raw or uncooked fish
Sh,3	Number of susceptible humans who often eat raw or uncooked fish
Ih,3	Number of infected humans who often eat raw or uncooked fish
Sh,4	Number of susceptible humans who very often eat raw or uncooked fish
Ih,4	Number of infected humans who very often eat raw or uncooked fish
Ss	Number of susceptible snails
Is	Number of infected snails
Sf	Number of susceptible fish
If	Number of infected fish