These cover a spectrum that includes the following.
- Temporal models are mostly based on compartmental SEIR(Susceptible, Exposed, Infected and Removed) models for epidemics but with additional complexities of:
- dual sources of inoculum;
- quenching as hosts become resistant to infection;
- and host dynamics that depend upon infection load.
- Stochastic modelsinclude allowance for:
- demographic stochasticity (chance effects in transmission from infected to susceptible individuals under otherwise identical conditions);
- environmental stochasticity (when transmission parameters are influenced by local or global changes in environmental variables).
- Spatially-implicit modelsseek to capture some of the spatial aspects of epidemics within a temporal model by using:
- non-linear mixing terms between susceptibles and infected;
- moment closure and pair-approximation methods.
- Spatially-explicit modelsinclude:
- individual-based models, for example, for susceptibles on a lattice often with local mixing;
- reaction-advection-diffusion and dispersal-kernel models;
- metapopulation models that comprise coupled sub-populations such as fields or different regions.