A differential equations model of east coast fever transmission dynamics
In this study a differential equation model of the transmission dynamics of East Cost Fever caused by Theileria parva transmitted by Rhippicephalus appendiculatus was developed. In this model cattle were assigned to four categories: susceptible, T. parva incubating, infectious (clinically infected) and recovered cattle population having immunity and still infect ticks but at a lower rate. Ticks were also categorized into various stages: eggs, larvae, susceptible nymphs, infected nymphs, susceptible adult ticks and infected adult ticks. The parameters of the model were obtained from literature assumed or calculated. Simulations with R software were run with and without seasonal questing activity of adult ticks. The results of the simulation model explained the seasonal differences of R. appendiculatus activity and transmission of T. parva between tropical eastern and central Africa and sub – tropical southern Africa. Besides, it showed that nymphs are the stage of R. appendiculatus that play important role in transmission of T. parva in southern Africa while both nymphs and adults transmit in eastern and central Africa. Future developments and data required to further develop the model were proposed.
Keywords: A model, Differential equations, Rhipicephalus appendiculatus, Theirelia parva