TABLE 1. COVID-19 workplace notifications,* investigations, and outbreaks,^† by priority classification^§ — Seattle & King County, Washington, June 15–November 15, 2020.

Workplace status	Priority
	Total	High	Medium	Low	Unknown
Notifications, no.	2,881	1,770	702	378	31
Investigated, no. (%)	1,305 (45.3)	1,085 (61.3)	191 (27.2)	26 (6.9)	3 (9.7)
Outbreak identified, no. (%)	524¶ (18.2)	489 (27.6)	28 (4.0)	7 (1.9)	0 (—)

Abbreviation: RT-PCR = reverse transcription–polymerase chain reaction.

* Workplaces met the investigation threshold if at least one COVID-19 patient attended work while contagious or two or more COVID-19 patients from the same workplace reported symptom onset within 14 days (or received a positive SARS-CoV-2 RT-PCR or antigen test result if asymptomatic). Period of contagiousness was defined as 2 days before onset of any symptoms (or 2 days before the date of specimen collection for a confirmed laboratory test in asymptomatic persons) through the beginning of isolation.

^† A workplace outbreak (cluster) was defined by the Washington State Department of Health as the occurrence of two or more cases of RT-PCR- or antigen-confirmed cases of SARS-CoV-2 infection from the same workplace in which symptom onset occurred within 14 days (or positive laboratory test result if asymptomatic), a plausible epidemiologic link in the workplace, and no known epidemiologic link outside the workplace.

^§ Priority levels were assigned based on workplace features assumed to be associated with increased COVID-19 spread, and workforce features associated with severe disease outcomes.

^¶ An outbreak determination was not available for two workplaces.