Your social network might lead to disease

A study of the passing of swine flu among a set of schoolchildren found that the disease was primarily spread through one’s social network:

A new study of a 2009 epidemic at a school in Pennsylvania has found that children most likely did not catch it by sitting near an infected classmate, and that adults who got sick were probably not infected by their own children.

Closing the school after the epidemic was under way did little to slow the rate of transmission, the study found, and the most common way the disease spread was a through child’s network of friends…

The scientists collected data on 370 students from 295 households. Almost 35 percent of the students and more than 15 percent of their household contacts came down with flu. The most detailed information was gathered from fourth graders, the group most affected by the outbreak.

The class and grade structure had a significant effect on transmission rates. Transmission was 25 times as intensive among classmates as between children in different grades. And yet sitting next to a student who was infected did not increase the chances of catching flu.

Social networks were apparently a more significant means of transmission than seating arrangements. Students were four times as likely to play with children of the same sex as with those of the opposite sex, and following this pattern, boys were more likely to catch the flu from other boys, and girls from other girls.

This sounds like a very interesting dataset as it was collected in real-time as the disease spread. Hopefully, we will get more data like this in the future so that we aren’t left with the problem of trying to trace a disease’s spread after the fact. But getting this kind of data would require more intense observation (or records) of a specific group of people.

If closing the school is not the answer, how then should authorities respond in order to slow down the spread of disease?

Sounds like another advantage for Social Networking Sites where you can interact with your friends with only the threat of a computer virus…

Obesity as “social contagion”

Findings in recent years that certain medical conditions, such as obesity, are strongly influenced by social networks have seemed to shake up thinking about how such conditions spread. A new model that explores obesity as a “social contagion” suggests obesity will eventually “spread” to at least 42% of the US population:

The social contagion hypothesis garnered widespread attention in 2007 when researchers from UC San Diego, documented that obesity can spread through a social network — just like viruses spread — because people “infect” each other with their perceptions of weight. That study was published in the New England Journal of Medicine, and subsequent research has confirmed the validity of the social contagion theory.

In a paper published Thursday in the journal PLoS Computational Biology, Harvard scientists applied a mathematical model of social contagion to 40 years of data from the Framingham Heart Study, a study that has followed more than 5,000 adult residents of Framingham, Mass., since 1948 to assess their heart health. Among the participants of that study, obesity increased from 14% in the 1970s to 30% in 2000 and continues to increase. Based on that data, the rapid upswing in obesity rates is due largely to social-network influence, said the authors of the new study. But, they noted, any subsequent rise in obesity rates will be slower than it has in the past. It may take another 40 years to reach that 42% obesity mark.

Interesting findings and I bet it is a complicated (but interesting) method by which such models are constructed.

If similar models were applied to other conditions or diseases, what are the results? In addition to obesity, what conditions are strongly influenced by social networks? Additionally, how can social networks be changed or altered so that an issue like obesity is combated?