A comparison of heterogeneity in the acquisition of varicella zoster virus and parvovirus B19 for five different European countries.

Abstract

We model the age-dependent force of infection for varicella zoster virus and parvovirus B19 based on a joint model while incorporating individual unobserved heterogeneity. Individual heterogeneity comprises the differences among individuals’ susceptibility to acquire infections, often referred to as `frailties'. We use a shared gamma frailty to describe this heterogeneity, assuming that the frailty distribution is the same for both infections and contrast this using a correlated frailty approach, relaxing upon this assumption.