Table 1.

Number of Enrolled Patients With Acute Respiratory Illness Tested, Positive Tests and Enrollment Dates for Severe Acute Respiratory Syndrome Coronavirus 2–Positive Patients, and Date of First Reported Nontravel-related Coronavirus Disease 2019 by Study Population, January 2020–March 2020

				Severe Acute Respiratory Syndrome Coronavirus 2
Study Site	Surveillance Counties	Time Period	No. Enrolleda	No. Tested	No. Positive (%)	Date of Enrollment	Date of First Reported Coronavirus Disease 2019 Caseb
Ann Arbor and Detroit, Michigan	10 counties in southeast Michigan	23 January–13 March	1026	848	2 (0.2)	9 March, 11 March	10 March
Pittsburgh, Pennsylvania	Allegheny	27 January–22 March	1294	1260	2 (0.2)	3 March, 11 March	7 March
Nashville, Tennessee	7 counties in central Tennessee	1 February–21 March	226	226	0 (0)	NA	5 March
Temple, Texas	8 counties in central Texas	25 January–5 March	875	584	0 (0)	NA	13 March
Seattle, Washington	King, Pierce, and Snohomish	31 January–29 February	1619	1214	1 (0.1)	25 February	21 February
Marshfield, Wisconsin	Clark, Marathon, and Wood	5 February–13 March	1367	660	0 (0)	NA	16 March
All sites		23 January–22 March	6407	4792	5 (0.1)

Abbreviation: NA, not applicable.

^aIncludes ambulatory patients aged ≥6 months and hospitalized adults aged ≥18 years who presented to healthcare facilities with acute respiratory illness.

^bDate of first reported COVID-19 case associated with community transmission in surveillance county.