The spread of influenza-like-illness within the household in Shanghai, China.

High-density urban habitats provide a hotbed for the rapid spread of infectious diseases. School children densely aggregate in classrooms. So schools are high incidence area of infectious diseases. This paper aims at investigating the transmission of influenza-like-illness within households with a school child using a survey study of fourth grade elementary school students in Shanghai, China. We found that the pairwise transmission probability within a household is only 0.172, which implies that the average number of infections caused by a single infectious individual in a household in Shanghai is only 0.304. Thus, the majority of transmission must occur outside of a household for a disease to cause an outbreak.