Featured Research

from universities, journals, and other organizations

'Friendship paradox' may help predict spread of infectious disease

Date:
September 16, 2010
Source:
University of California - San Diego
Summary:
Researchers used a basic feature of social networks to study the 2009 flu epidemic. The findings, they say, point to a novel method for early detection of contagious outbreaks.

The largest component, 714 people, of the social network studied by Fowler and Christakis, on Dec. 8, 2009. Infected individuals are colored red, friends of infected individuals are colored yellow.
Credit: Image courtesy of University of California - San Diego

Your friends are probably more popular than you are. And this "friendship paradox" may help predict the spread of infectious disease.

Nicholas Christakis, professor of medicine, medical sociology and sociology at Harvard University, and James Fowler, professor of medical genetics and political science at the University of California, San Diego, used the paradox to study the 2009 flu epidemic among 744 students. The findings, the researchers say, point to a novel method for early detection of contagious outbreaks.

Analyzing a social network and monitoring the health of its central members is an ideal way to predict an outbreak. But such detailed information simply doesn't exist for most social groups, and producing it is time-consuming and expensive.

The "friendship paradox," first described in 1991, potentially offers an easy way around this. Simply put, the paradox states that, statistically, the friends of any given individual are likely more popular than the individual herself. Take a random group of people, ask each of them to name one friend, and on average the named friends will rank higher in the social web than the ones who named them.

If this is hard to fathom, imagine a large cocktail party with a host holding court in the center while, at the fringes, a few loners lean against the walls staring at their drinks. Randomly ask the party-goers to each name a friend, and the results will undoubtedly weigh heavily in the direction of the well-connected host. Few people will name a recluse.

And just as they come across gossip, trends and good ideas sooner, the people at the center of a social network are exposed to diseases earlier than those at the margins.

As the 2009 influenza season approached, Christakis and Fowler decided to put these basic features of a social network to work, contacting 319 Harvard undergraduates who in turn named a total of 425 friends. Monitoring the two groups both through self-reporting and data from Harvard University Health Services, the researchers found that, on average, the friends group manifested the flu roughly two weeks prior to the random group using one method of detection, and a full 46 days prior to the epidemic peak using another method.

"We think this may have significant implications for public health," said Christakis. "Public health officials often track epidemics by following random samples of people or monitoring people after they get sick. But that approach only provides a snapshot of what's currently happening. By simply asking members of the random group to name friends, and then tracking and comparing both groups, we can predict epidemics before they strike the population at large. This would allow an earlier, more vigorous, and more effective response."

"If you want a crystal ball for finding out which parts of the country are going to get the flu first, then this may be the most effective method we have now," said Fowler. "Currently used methods are based on statistics that lag the real world -- or, at best, are contemporaneous with it. We show a way you can get ahead of an epidemic of flu, or potentially anything else that spreads in networks."

Indeed, the authors note that the same method could be used very widely -- to anticipate epidemics of behaviors like drug use or even the diffusion of ideas or fashions.

John Glasser, a mathematical epidemiologist at the Centers for Disease Control in Atlanta, GA, who was not involved in this research, said: "Christakis' and Fowler's provocative study should cause infectious disease epidemiologists and public health practitioners alike to consider the social contexts within which pathogens are transmitted. This study may be unique in demonstrating that social position affects one's risk of acquiring disease. Consequently, epidemiologists and social scientists are modeling networks to evaluate novel disease surveillance and infection control strategies."

The study, published by PLoS ONE, was funded by Harvard University.

Fowler and Christakis are coauthors of "Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives.


Story Source:

The above story is based on materials provided by University of California - San Diego. Note: Materials may be edited for content and length.


Journal Reference:

  1. Nicholas A. Christakis, James H. Fowler. Social Network Sensors for Early Detection of Contagious Outbreaks. PLoS ONE, 5(9): e12948 DOI: 10.1371/journal.pone.0012948

Cite This Page:

University of California - San Diego. "'Friendship paradox' may help predict spread of infectious disease." ScienceDaily. ScienceDaily, 16 September 2010. <www.sciencedaily.com/releases/2010/09/100915150949.htm>.
University of California - San Diego. (2010, September 16). 'Friendship paradox' may help predict spread of infectious disease. ScienceDaily. Retrieved September 18, 2014 from www.sciencedaily.com/releases/2010/09/100915150949.htm
University of California - San Diego. "'Friendship paradox' may help predict spread of infectious disease." ScienceDaily. www.sciencedaily.com/releases/2010/09/100915150949.htm (accessed September 18, 2014).

Share This



More Science & Society News

Thursday, September 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Stocks Hit All-Time High as Fed Holds Steady

Stocks Hit All-Time High as Fed Holds Steady

AP (Sep. 17, 2014) The Federal Reserve signaled Wednesday that it plans to keep a key interest rate at a record low because a broad range of U.S. economic measures remain subpar. Stocks hit an all-time high on the news. (Sept. 17) Video provided by AP
Powered by NewsLook.com
Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Space Race Pits Bezos Vs Musk

Space Race Pits Bezos Vs Musk

Reuters - Business Video Online (Sep. 16, 2014) Amazon CEO Jeff Bezos' startup will team up with Boeing and Lockheed to develop rocket engines as Elon Musk races to have his rockets certified. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
President To Send 3,000 Military Personnel To Fight Ebola

President To Send 3,000 Military Personnel To Fight Ebola

Newsy (Sep. 16, 2014) President Obama is expected to send 3,000 troops to West Africa as part of the effort to contain Ebola's spread. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins