Dyad Models for Childhood Epidemics

Introduction Measles is one of the most communicable infectious diseases. Prior to immunisation, measles was a common childhood disease even in developed countries with over 90% of the population having been infected by age 20. In young and malnourished children measles may be fatal in between 5% and 10% of the cases and so is responsible for many deaths in the developing world. Figure 1 near here The prediction of measles epidemics and dynamics is undoubtedly very important from a public health view; however the understanding of measles has become a goal to many epidemiologists as it possesses complex dynamics, yet a very simple natural history and many plausible population models (Hamer 1906, Bartlett 1957, Schwartz 1985, Olsen 1987, Schenzle 1984, and Bolker and Grenfell 1993). The data for measles is very long and detailed in comparison to other ecological time series and thus it is possible to obtain a picture of the long term dynamics of this disease. A