Table 2.

Performance characteristics of the rapid antigen detection test for the presence of SARS-CoV-2 virus in 160 respiratory samples^a.

Sample type	All samples (N = 160)					High viral load samples (N = 64)					Normal viral load samples (N = 96)
	Ct value		No. of samples			Ct value		No. of samples			Ct value		No. of samples
	mean	range	tested	positive	sensitivity	mean	range	tested	positive	sensitivity	mean	range	tested	positive	sensitivity
NPA & TS	20.72	13.80−29.95	35	12	34.3%	16.08	13.80−17.95	11	9	81.8 %	22.84	18.69−29.95	24	3	12.5%
NPS & TS	19.35	13.67−29.79	35	16	45.7 %	16.36	13.67−18.52	20	16	80.0%	23.33	18.79−29.79	15	0	0.0%
sputum	22.91	15.32−31.12	45	5	11.1 %	16.98	15.32−18.14	7	2	28.6 %	24.00	19.43−31.12	38	3	7.9%
throat saliva	19.65	11.25−30.81	45	18	40.0%	15.16	11.25−18.49	26	14	53.8%	25.79	19.20−30.81	19	4	21.1 %

^aHigh viral load samples means samples with Ct values <18.57 of SARS-CoV-2 virus–specific RT-PCR while normal viral load samples mean samples with Ct values >18.57.