ABSTRACT
This chapter discusses epidemic chain models which result when either heterogeneity between individuals or heterogeneity between households is explained by taking the parameters of certain chain binomial models as random variables. It provides the terms ‘fixed effects’ and ‘random effects’ in the same sense as they are used in the standard analysis of variance. Allow infectives to differ in their infectiousness by assigning to each infected individual an infectiousness function chosen independently and at random from a set of possible infectiousness functions. For some diseases there is evidence that infected individuals reach different levels of infectiousness and remain infectious for different periods of time. The chapter examines the chain binomial model to allow infectives to differ in their infectiousness. If the households can be classified a priori into homogeneous groups of households, then a multi-parameter chain binomial model can be used for the analysis.
