Table 2.

Characteristics of confirmed SARS-CoV-2 infections in former Q fever patients and comparison between former Q fever patients and matched persons in the general population in Region A (Q fever region; n = 73), Region B (non-Q fever region; n = 73) and Region A and B together (n = 146) in the Netherlands

	Former Q fever patients		General population in Region A				General population in Region B				General population in Region A and B combined
	n	%	n	%	OR	95% CI	n	%	OR	95% CI	n	%	OR	95% CI
Period 1: February 2020–June 2020a	21		21				21				42
Hospitalisation	11	52.4	11	52.4	1.00	0.32–3.10	9	42.9	1.33	0.46–3.84	20	47.6	1.21	0.42–3.44
ICU	5	26.3	2	9.5	2.50	0.49–12.9	3	14.3	2.50	0.49–12.9	5	11.9	2.91	0.68–12.5
Death	6	29.6	6	28.8	1.00	0.20–4.96	5	23.8	2.00	0.18–22.1	11	26.2	1.24	0.25–6.06
Period 2: September 2020–February 2021b	52		52				52				104
Hospitalisation	3	5.9	1	1.9	3.00	0.31–28.8	2	3.9	1.50	0.25–8.98	3	2.88	2.00	0.40–9.91
ICU	0	0	0	0	NA	NA	1	1.9	NA	NA	1	0.96	NA	NA
Death	3	5.8	0	0	NA	NA	2	3.9	1.50	0.25–8.98	2	1.92	3.00	0.50–18.0
Total period: February 2020–February 2021	73		73				73				146
Hospitalisation	14	19.2	12	16.4	1.29	0.48–3.45	11	15.1	1.38	0.55–3.42	23	15.8	1.40	0.58–3.41
ICU	5	6.9	2	2.7	2.50	0.49–12.9	4	5.5	1.67	0.40–6.97	6	4.11	2.19	0.58–8.36
Death	9	12.3	6	8.2	2.00	0.50–8.00	7	9.6	1.67	0.40–6.97	13	8.90	1.85	0.56–6.16

OR, odds ratio; CI, confidence interval; ICU, intensive care unit; NA, not applicable.

^aSARS-CoV-2 PCR test capacity was limited during this period. Only health care workers, the elderly, persons with comorbidities and hospitalised patients could get tested.

^bSARS-CoV-2 PCR (and later also antigen) tests were available for everyone with COVID-19-related symptoms.