Geographic and temporal development of plagues

ALTHOUGH deterministic and stochastic descriptions of localised epidemics abound in the literature of epidemiology and quantitative biology1,2, the geographic spread of epidemics has not been analyzed in such detail. (Although in ref. 2, page 205, Bailey gives equations similar in spirit to my equation (1) they seem to lack physical significance.) Realistic mathematical models of the geotemporal development of plagues could be useful in the study of epizootics (that is, in ecology, wildlife management or veterinary medicine), of social phenomena (such as the spread of drug abuse or fads), and of history. Needless to say, such models should also be applicable to public health questions.