Social media is largely thought of as a way for people across the world to keep in touch and share moments from their lives. The information being collected on sites like Twitter and Facebook, however, can also be used for both good and bad ends. The Infectious Diseases Society of America today revealed one way in which social media has helped health officials track an outbreak to its source.

In 2012, 63 people attended a high school dance team banquet for a Minnesota high school, and 18 of them came down with a case of strep throat in the days following. Facebook posts about the illness soon began popping up, and one concerned parent connected the dots and called the Minnesota Department of Health. The department swung into action, interviewing around 100 people connected to the banquet and their families. Health officials then typed the DNA of the strep throat strains found in those who were sick. Using these techniques, the department was able to track down the source of the outbreak. A study on the outbreak was published this week in the journal Clinical Infectious Diseases.

The source of the outbreak turned out to be a pasta dish at the banquet that was prepared by a parent who had had the strep throat. The DNA of the bacteria samples taken from those who fell ill were matched to the bacteria found in the pasta. One of the sick persons had not attended the banquet, but had eaten leftovers from the event. The parent suspected of spreading the infection and a child from the same household had been sick with strep throat three weeks before the banquet.

“We suspect cooked food was contaminated by respiratory droplets from a person who carried the strep bacteria in the throat when the food was cooling or reheating,” said Dr. Sarah Kemble, lead author of the report and the leader on the investigation. “The food probably was not kept hot or cold enough to stop bacterial growth.”

Kemble and her colleagues at the health department cited the rapid, social nature of Facebook communication as playing “an important role” in bringing the outbreak to the attention of health authorities. The report also suggests that a “formalized” use of social media could help health departments in investigating outbreaks and conducting disease surveillance.