We recently started showing the Facebook community in the United States an opt-in symptom survey run by health researchers at Carnegie Mellon University. The survey asked people if they have symptoms such as fevers, coughing, shortness of breath or loss of smell that are associated with covid-19. Since experiencing symptoms is a precursor to becoming more seriously ill, this survey can help forecast how many cases hospitals will see in the days ahead and provide an early indicator of where the outbreak is growing and where the curve is being successfully flattened. The survey responses are sent to the researchers and aren’t accessible to Facebook.

On Monday, the team at Carnegie Mellon is publishing its initial findings. They’re getting approximately 1 million responses a week in the United States, and the results are promising. They correlate with publicly available data on confirmed cases, which suggests this data can help predict where the disease will spread. They can also be used to build detailed county-by-county insights. The results indicate, for example, that in some New York City suburbs, an estimated 2 to 3 percent of people are experiencing covid-19-like symptoms. Using aggregate data from Carnegie Mellon’s results, Facebook produced its first report and new interactive maps, which we plan to update daily through this outbreak.