Table 1.

Results from the PHA's population tests to monitor the spread of COVID-19 during 2020.

Area	Test dates	Ongoing infection	Sample size
Stockholm	March 26–April 3	2.5%	n = 738
Sweden	April 21–24 (a)	0.9%	n = 2,571
Stockholm	April 21–24 - subsample of (a)	2.3%	n = 679
Sweden	May 25–28 (b)	0.3%	n = 2,957
Stockholm	May 25–28 - subsample of (b)	0.7%	n = 761
Sweden	August 24–28	No one	n = 2,518
Sweden	September 21–25	No one	n = 2,461
Sweden	November 30–December 4 (c)	0.7%	n = 2,983
Stockholm	November 30–December 4 - subsample of (c)	1.0%	n = 790

Source: PHA.