SWB prevalence strata: | Â |
---|---|
  k Δw ≤ w < (k + 1)Δw | {h k (t) : k = 0, 1, …} |
 with worm burden increment Δw | ∑ k h k  = 1 |
Demographically structured SWB: | Â |
 Child | h C k (t) |
 SAC | h S k (t) |
 Adult | h A k (t) |
Population densities per unit habitat: | Â |
 human | H(t) |
 SEI (susceptible, infected, patent) snail | N(t) = x(t) + y(t) + z(t) |