Implements the XH component using a Susceptible-Exposed-Infectious-Susceptible (SEIS) compartmental model of human infection dynamics. This is an SEI model without lasting immunity: individuals return directly to susceptibility after clearing infection.
Htotal human (or host) population density
Edensity of exposed (infected but not yet infectious) humans
Idensity of infectious humans
Note: susceptible density \(S = H - E - I\).
btransmission probability from mosquito to human
ctransmission probability from human to mosquito
nurate of progression from exposed to infectious
rclearance rate for infections
Btime-dependent birth rate function \(B(t, H)\)
Dlinear operator (matrix) for mortality, migration, aging, and transfers
$$ \begin{array}{rl} dH/dt &= B(t,H) + D \cdot H \\ dE/dt &= hS - \nu E + D \cdot E \\ dI/dt &= \nu E - rI + D \cdot I \\ \end{array}$$ where \(h\) is the force of infection and \(S = H - E - I\).