Basic Reproductive Number (R_{ 0 }) | The basic reproductive number, R_{ 0 }, is the average number of successful offspring that a parasite is capable of producing [12, 61]. For the compartmental models of malaria this is defined as the number of secondary cases of malaria arising from a single case in an otherwise uninfected population [40], and can be thought of as a measure of the intensity of transmission. The estimation of basic reproductive number (R_{ 0 }), from both models and data has been discussed by several researchers over the years [12, 59–61, 125]. Malaria can spread in a population only if R_{ 0 } > 1 (epidemic), but when it is maintained in a population without the need for external inputs R_{ 0 } = 1 (endemic). A disease free population is possible when R_{ 0 } < 1. These threshold conditions of R_{ 0 } may not hold for stochastic models. In that case the disease may go extinct even for R_{ 0 } > 1, depending on the magnitude of stochastic fluctuations around the endemic equilibrium state [12]. |