An epidemic chain model is developed by assuming a beta distribution for the probability of being infected by contact with a given infective from the same household. This model includes, as a particular case, the epidemic chain model corresponding to the stochastic Kermack-McKendrick model and, as a limiting case, the Reed-Frost chain binomial model. The advantages of the more general model are illustrated with an application to household data for the common cold. Finally, it is shown how the coefficient of variation of the duration of the infectious period may be estimated without any direct observations on this duration.