The Social Structure Underlying the Spread of Childhood Close-Contact Infectious Diseases. Combining Time Use and Contact Surveys to Explain Age-Specific Seroprevalence Profiles

Emilio Zagheni, University of California, Berkeley
Piero Manfredi, Università di Pisa

Demographic and social processes play an important role in preventing or sustaining the spread of infectious diseases in human societies. In this paper, we discuss the possibilities offered by two independent social data sources - time use data and contact surveys - to explain the observed age-specific seroprevalence profile for two close-contact childhood infections (varicella and parvovirus B19). We first discuss the epidemiological consequences of the assumption that age-specific potentially infectious contacts are proportional to self-reported age-specific number of social contacts or age-specific estimates of time of exposure. Then we propose a model that combines information from age-specific social contact and time of exposure matrices. The model is used to evaluate the impact of behavioral changes and specific interventions (e.g., school closure) on the spread of close-contact infections. Empirical analysis is based on data for Italy, where a comprehensive and up-to-date collection of serologic and social data is available.