Risk factors of influenza transmission in households by Cécile Viboud, Pierre-Yves Boëlle, Simon Cauchemez, Audrey Lavenu, Alain-Jacques Valleron, Antoine Flahault, and Fabrice Carrat BJGP Volume 54(506):684-689 September 1, 2004 ©2004 by British Journal of General Practice
Flow diagram of the study. Flow diagram of the study. Dotted boxes denote subjects included in the main analysis. Cécile Viboud et al. Br J Gen Pract 2004;54:684-689 ©2004 by British Journal of General Practice
Number of secondary cases of influenza by day of household outbreak. Number of secondary cases of influenza by day of household outbreak. Overall there were 131 secondary cases. Day 0 is the day of onset of influenza A (H3N2) illness in the index case = day of the visit to the general practitioner. Cécile Viboud et al. Br J Gen Pract 2004;54:684-689 ©2004 by British Journal of General Practice