Dynamics of Childhood Infections in High Birthrate Countries

The majority of the mathematical literature concerned with disease dynamics is concerned with transmission in populations of fixed size where net births balance net deaths. The current generation of models do not take account of case fatalities nor of positive population growth rates and are therefore of limited use to aid in data interpretation or for the design of optimal control policies in developing areas. A deterministic model for the epidemiology of an infectious disease which induces lifelong immunity is described. The model allows for age dependent case fatality rates and for population growth. Both equilibrium and dynamical results are discussed; the former in connection with the estimation of disease parameters from published data, and the latter with reference to the investigation of the possible effects of different vaccination strategies. Measles is used as an example throughout, and reference is made to the available data on the epidemiology of measles in tropical regions.