. 2021 Jan 5;4(1):e2033706. doi: 10.1001/jamanetworkopen.2020.33706

Table 1. Seroprevalence Estimates From SARS-CoV-2 Community Surveys in the US, April 10 to May 3, 2020.

Location	Population (millions)^a	Sample size, No.	SARS-CoV-2 seroprevalence (date of specimen collection), %	Estimated No. of persons with SARS-CoV-2 infection	Cumulative reported COVID-19 cases (date)^b	Underreporting multiplier
Location	Population (millions)^a	Sample size, No.	SARS-CoV-2 seroprevalence (date of specimen collection), %	Estimated No. of persons with SARS-CoV-2 infection	Cumulative reported COVID-19 cases (date)^b	Infection	Symptomatic
California (Los Angeles)⁵	9.4	863	4.6 (April 10-11)	434 031	13 069 (April 11)	33.2×	19.9×
Florida (Miami-Dade)⁶	2.7	1800	6.0 (April 15-20)	163 016	9657 (April 20)	16.9×	10.1×
Georgia (Dekalb-Fulton)⁷	1.8	696	2.5 (April 28-May 3)	45 581	5500 (May 3)	8.3×	5×
Indiana (statewide)⁸	6.7	3658	2.8 (April 25-29)	188 502	17 756 (April 29)	10.6×	6.4×
New York (statewide)⁹	19.4	15 101	14.0 (April 14-28)	2 723 498	299 691 (April 28)	9.1×	5.5×
All	NA	Total: 22 118	NA	NA	NA	Median: 10.6× (IQR, 9.1× to 16.9×)	Median: 6.4× (IQR, 5.5× to 10.1×)

Abbreviations: COVID-19, coronavirus disease 2019; IQR, interquartile range; NA, not applicable; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.

^{^a}

US Census Bureau quick factors (all-age population).

^{^b}

Cumulative reported COVID-19 cases derived from county and state health department websites.