# Quidel

• Source name: quidel
• Number of data revisions since 19 May 2020: 0
• Date of last change: Never
• Available for: msa, state (see geography coding docs)

Data source based on flu lab tests, provided to us by Quidel, Inc. When a patient (whether at a doctor’s office, clinic, or hospital) has COVID-like symptoms, doctors may perform a flu test to rule out seasonal flu (influenza), because these two diseases have similar symptoms. Using this lab test data, we estimate the total number of flu tests per medical device (a measure of testing frequency), and the percentage of flu tests that are negative (since ruling out flu leaves open another cause—possibly covid—for the patient’s symptoms), in a given location, on a given day.

The number of flu tests conducted in individual counties can be quite small, so we do not report these signals at the county level.

The flu test data is no longer updated as of May 19, 2020, as the number of flu tests conducted during the summer (outside of the normal flu season) is quite small. The data may be updated again when the Winter 2020 flu season begins.

Signal Description
raw_pct_negative The percentage of flu tests that are negative, suggesting the patient’s illness has another cause, possibly COVID-19
smoothed_pct_negative Same as above, but smoothed in time
raw_tests_per_device The number of flu tests conducted by each testing device; measures volume of testing
smoothed_tests_per_device Same as above, but smoothed in time