Evidence for a fractal stochastic process underlying measles epidemics in Britain

The variability in measles incidence during the pre-vaccination period of 1 944 to 1966, as recorded from 366 communities in England and Wales, was exa mined for properties of fractal stochastic processes. The power spectral de nsity, Fano factor, and Allan factor were computed from the incidence time- series, and all revealed power-law scaling. As well, the distribution histo gram for the weekly incidence approximated a geometric distribution. These features constituted evidence for a fractal stochastic process with underly ing geometric statistics at play in the development and resolution of measl es epidemics.