  Acute infectious diseases are transmitted over networks of social contacts.
Epidemic models are used to predict the spread of emergent pathogens and
compare intervention strategies. Many of these models assume equal probability
of contact within mixing groups (homes, schools, etc.), but little work has
inferred the actual contact network, which may influence epidemic estimates. We
develop a penalized likelihood method to infer contact networks within
households, a key area for disease transmission. Using egocentric surveys of
contact behavior in Belgium, we estimate within-household contact networks for
six different age compositions. Our estimates show dependency in contact
behavior and vary substantively by age composition, with fewer contacts
occurring in older households. Our results are relevant for epidemic models
used to make policy recommendations.
