Collecting social contact data in the context of disease transmission: Prospective and retrospective study designs

Patterns of direct contacts between people ultimately determine the transmission rate for airborne pathogens like influenza; therefore, data regarding contact behaviour are essential for designing infectious disease control. In order to collect reliable data about social contacts, decisions about the survey methodology have to be made. A series of relevant surveys was conducted in 2003–2006 among university students in Bielefeld, Germany. Each survey focussed on specific methodological questions related to the number of contacts encountered during 1 day. In this study, we report on the analysis of different survey designs.