Compartmental construction of the epidemiological model for Chikungunya transmission.

<p>Susceptible humans (S) are exposed to infection (E) before becoming infectious (I_a asymptomatically, or I symptomatically) and then recover (R). Susceptible mosquitoes (X) are exposed to infection (Y) before becoming infectious (Z). Transmission from mosquito-to-human and vice versa is denoted by the broken lines indicating a mosquito bite. Rates of change between compartments are denoted by corresponding Greek letters.