Theoretical models help us understand infectious diseases 口Susceptible(St) Birth------ Infected (1) Recovered(Rt) XSIS Susceptible Infected People can move from group to group ViSt Susceptible infected, recovered,or death Recovered Infected→recovered Ad St Xdlt or death ▣Recovered→death Death Bhattacharya,Hyde and Tu-HealthEconomics Bhattacharya, Hyde and Tu – Health Economics Theoretical models help us understand infectious diseases  Susceptible (St )  Infected (It )  Recovered (Rt )  People can move from group to group  Susceptible → infected, recovered, or death  Infected → recovered or death  Recovered → death