"The estimates can be helpful for policymakers and health researchers to forecast potential COVID-19 outbreaks. These estimates don’t represent confirmed COVID-19 cases and shouldn’t be used for diagnostic or treatment purposes, or guidance on personal or business travel. Facebook’s research partners are committed to only using survey results to study and help contain COVID-19."

The dataset is explicitly not intended for general public consumption, and having access to flu and COVID symptom overlap is important for epidemiology research and disease surveillance.

Ah! But his map isn't a representation of COVID-19 cases.

It's a representation of people who self diagnose symptoms that are associated with COVID-19.

The small print below the map matters:

> This map shows an estimated percentage of people with COVID-19 symptoms, not confirmed cases.

The self diagnose part is important as well, because people are asked to observe themselves and fill out a survey through Facebook. They don't take a test administered by a health expert and report the exact results back.

Put differently, you're looking at a map of people who report recognizing symptoms with themselves that are associated with COVID-19. But are also associated with the flu or any other respiratory affliction ranging from the common cold over allergies to early lung cancer.

Maybe because the syndromes that medical facilities report to health depts are ILI (influenza like illness) & ARDI (acute respiratory distress illness) and this tool is trying to put a common name to the survey?