A problem in the theory of epidemics, II

摘要: Abstract In an earlier article the authors considered a deterministic epidemic model that accounts for certain threshold phenomena occuring in spread of infection. The present includes major modification allows individuals recovered from infection to eventually become susceptible again A set five integral equations is derived basic assumptions concerning theorem asserts existence, uniqueness, and continuous dependence solution these equations. proof results accomplished by contraction mapping argument also gives simple result. minor included, which brings into scope this study some older models. Some numerical computation carried out problem described.