It's colds and flu season, and as any parent knows, colds and flu spread like wildfire, especially through schools.
New research using human-networking theory may give a clearer picture of just how, exactly, infectious diseases such as the common cold, influenza, whooping cough and SARS can spread through a closed group of people, and even through populations at large.
With the help of 788 volunteers at a high school, Marcel Salath, a biologist at Penn State University, developed a new technique to count the number of possible disease-spreading events that occur in a typical day.
This results are published in this week's issue of the journal Proceedings of the National Academy of Sciences.
The research was funded by the National Science Foundation (NSF) and the National Institutes of Health (NIH).
"Contact networks, which are shaped by social and cultural processes, are keys to the spread of information and infection," says Deborah Winslow, NSF program director for cultural anthropology and the ecology of infectious diseases. "Before this research, the study of contact networks had been hampered by the lack of good data on their formation and structure."
"This setting proved a closed population in which the whole network could be determined. By collecting real-time network data, the researchers improved significantly on the usual error-prone techniques that depend on asking informants to recall their interactions."
Every day people come into contact with many other people; their interactions vary in length; and each contact is an opportunity for a disease to spread, Salath said.
"But it's not like you can take a poll and ask people, 'How many different people have breathed on you today, and for how long?' We knew we had to figure out the number of person-to-person contacts systematically."
Using a population of high-school students, teachers and staff members as a model for
|Contact: Cheryl Dybas|
National Science Foundation