Although many people worry about the negative effects of social media on teenagers, one Minnesota parent used a child’s Facebook posts to alert public health officials about a large foodborne outbreak of strep throat.
Strep throat, or Group A Streptococcus (GAS) pharyngitis, generally spreads from person to person by respiratory droplets, but transmission from contaminated food does occur. Among 63 people who ate at a high school dance team’s banquet, 18 developed symptoms of strep throat within 3 days. Multiple posts soon appeared on the group’s Facebook page. Mounting reports of ill team members and relatives prompted a concerned parent to notify the state health department. The full report is published online in Clinical Infectious Diseases.
Investigators interviewed approximately 100 people by telephone, including those who attended the banquet, household contacts of attendees, and those who did not attend but ate the leftovers. Using pulse field gel electrophoresis, they compared the DNA fingerprints of the strep isolates collected from those who developed GAS infection and from samples of leftover food.
The most likely source of the outbreak was pasta served at the banquet, reported Sarah Kemble, MD, and a team of investigators from the Minnesota Department of Health. Bacteria from the throats of those who became ill after attending the banquet matched bacteria identified in the pasta. One person who did not attend the banquet but ate some leftover pasta brought home by family members developed a laboratory-confirmed GAS infection that matched the same DNA fingerprint pattern, helping confirm the route of transmission. No one else in the household had symptoms of strep throat, and throat swabs on all the other household members were negative for GAS.
The researchers said they suspect that someone who carried strep bacteria in the throat unknowingly contaminated the food during preparation. “The food probably was not kept hot or cold enough to stop bacterial growth,” said Kemble in a statement. Both the parent who prepared the pasta and a child in the same household reported having strep throat 3 weeks before the banquet.
Rapid, real-time communication within a large group using online social media played a critical role in bringing this outbreak to the attention of public health authorities. Previous work has demonstrated the utility of search engines and social media to accurately track influenza activity. Google.org, which launched Google Flu Trends in 2008, subsequently developed Google Dengue Trends to help track outbreaks of illness caused by the mosquito-borne dengue virus and provide users and public health officials with timely estimates of dengue activity in their region. The organization said that it has found a close relationship between the number of people searching for dengue-related topics and how many people actually have dengue symptoms.
In coming years, social media will likely play an increasing role in disease surveillance and outbreak investigations. The US Department of Homeland Security, for example, has funded a $3 million pilot program to link and analyze data from social media networks to help the Office of Health Affairs “better inform and protect the public in the event of a national health emergency such as an infectious disease outbreak or a biological attack.” Recognition of the potential of social media to aid in epidemiologic investigations could be a major boon to public health, especially in the current era of shrinking budgets.