Table 1.

Rates of SARS-CoV-2 seropositivity (IgGs against either nucleocapsid or spike 1 proteins) among healthcare workers from five hospitals. Individuals were assessed over a 13 (London) or 10 (Nottingham) week period between 23 March 2020 and 10 July 2020 and are considered seropositive if they showed seropositivity at any time point during this longitudinal assessment.

		London				Nottingham
		Ab-	Ab+	Seropositive%		Ab-	Ab+	Seropositive%
Hospital	City Hospital					165	37	18.3%
	QMC					353	78	17.9%
	Barts/Nightingale	403	101	20.0%
	Royal Free	171	56	24.7%
	Total	574	157	21.5%		518	115	18.2%
Age	Mean years	37.8	39.4			43.1	43.9
	(SD)	10.9	11			11.6	11.6
BMI	Mean kg/m2	25.0	25.6			26.5	26.9
	(SD)	4.5	4.4			4.8	5.0
Sex	M	188	54	22.3%		115	22	16.1%
	F	384	102	21.0%		401	93	18.7%
	Other/Unspec	2	1	33.3%		2	0	0.0%
Case definition*	Yes	111	71	39.0%		108	42	28.0%
Covid-19	No	463	86	15.7%		410	73	15.1%
symptoms
Ethnicity	Asian	126	25	16.6%		46	12	20.7%
	South Asian	67	12	15.2%		40	10	20.0%
	East Asian	57	13	18.6%		6	2	25.0%
	OtherAsian	1	2
	Black	24	18	42.9%		10	7	41.2%
	Other/Mixed	46	6	11.5%		24	9	27.3%
	Unspecified	6	1	14.3%		1	0
	White	372	107	22.3%		439	87	16.5%
IMD decile	1-3	138	46	25.0%		98	29	22.8%
	4-7	265	76	22.3%		177	38	17.7%
	8-10	73	21	22.3%		130	29	18.2%
	Unspecified	98	14	12.5%		113	19	14.4%
Use of PPE	ITU role	109	17	13.5%		36	1	2.7%
	use PPE not ITU	353	112	24.1%		337	84	20.0%
	other roles	112	28	20.0%		147	30	16.9%
Hospital role	Doctor	115	35	23.3%		68	20	22.7%
	Nurse/AHP	386	98	20.2%		312	67	17.7%
	Clinical Support worker	7	3	30.0%		10	1	9.1%
	other	67	20	23.0%		128	27	17.4%

ITU= intensive therapy unit; AHP = allied healthcare professional; clinical support worker includes portering and cleaning staff

^⁎the clinical criteria for assessing possibility of infection with COVID-19 based on characteristic symptoms