Simple Epidemic Process with Gamma Interinfection Time

Document Type : Original Article

Authors

Institute of Statistical Studies & Research, Cairo University, Egypt

Abstract

This paper deals with the derivation of the distribution of the number of infectives in a simple epidemic for a small population size N. This derivation is in kind of a convolution of gamma (r,λi) interinfection times, in both cases of repeated and unrepeated infection rates λi. The duration time distribution of a simple epidemic is also obtained. It was found that the results are a generalization of those of Billard and al (1979) who assumed exponential interinfection time with infection rate λi = i (N-i) Numerical examples are presented.

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