EFFECT OF VARIABILITY IN INFECTION PERIOD ON THE PERSISTENCE AND SPATIAL SPREAD OF INFECTIOUS-DISEASES

The effects of the mean infection (incubation plus infectious) period on the dynamics of infectious diseases are well understood. We examine the dynamics and persistence of epidemics when the distribution of th e infection period also is modelled, using the well-documented childho od disease measles as a test case. We pay particular attention to the differences between exponentially distributed and constant periods. Th e use of constant periods increases the persistence of epidemics by re ducing the individual stochasticity. The infection period distribution is also shown to have a significant effect on the spatial spread of d isease. (C) 1998 Elsevier Science Inc.