Figure 1

Compartmental diagram of our malaria transmission model. Each compartment in the diagram represents a different epidemiological class. Individuals begin in the susceptible naïve class (S _N ), return there after losing clinical immunity, at a rate α, and are born into this class, at a rate μ. Individuals in S _N who get infected move to the infected naïve class (I _N ), at a rate Λ. From I _N , individuals recover from illness to either the susceptible naïve class (S _N ), at a rate γ _NN , if immunity was not conferred, or to the susceptible clinically immune class (S _C ), at a rate γ _NC if clinical immunity developed. Individuals who are susceptible clinically immune can either lose immunity at a rate α and return to the susceptible naïve class, or they can get infected, at a rate σ Λ, and become infected clinically immune (I _C ). Infected clinically immune individuals recover to the susceptible clinically immune class, at a rate γ _C . Individuals can die from any of the epidemiological classes and do so at a rate μ independent of the level of malaria in the population. Individuals are born and die at the same rate, thus keeping the population size constant.