THE DETERMINISTIC SIMPLE EPIDEMIC UNMASKED

We derive a simple but surprising connection between the ''determinist ic epidemic with recovery'' and the spatial birth-and-death process, a nd discuss its implications for the use of nonlinear differential equa tion models for the spatial spread of epidemics. This paper consists o f a manuscript dating back to 1977, which has been widely referred to in the literature but not previously published, and its more recent ex tension to include recovery/death in the processes considered, with so me additional comments. To aid reference, we retain the original title .