TABLE 2.

Low-titer SARS-CoV-2-positive nasopharyngeal swab specimens in five-specimen pools^a

Positive sample	No. of PCR-positive pools/no. of pool replicates	N1			N2
		Sample CT	Pool CTb	ΔCTb	Sample CT	Pool CTb	ΔCT (range)b
A	3/3	35.56	35.89	0.33	35.63	36.40	0.81
B	3/3	35.15	34.70	−0.45	34.29	36.09	1.80
C	3/3	36.13	36.52	0.39	38.05	36.81	−1.24
D	3/3	36.23	35.31	−0.92	39.07	36.83	−2.24
E	3/3d	33.36	34.80	1.44	33.98	38.49	4.51
F	3/3	33.49	35.24	1.75	34.78	36.33	1.55
G	3/3	33.33	33.28	−0.05	35.10	34.42	−0.68
H	3/3	33.09	35.03	1.94	34.06	36.78	2.72
I	3/3	33.03	34.04	1.01	33.86	35.23	1.37
J	3/3	33.34	33.53	0.19	34.00	35.89	1.89
K	2/3c,d	34.92	36.88	1.96	37.69	38.56	0.90
L	3/3	34.63	36.43	1.80	36.36	39.31	2.95
M	3/3d	34.84	35.90	1.06	36.11	36.29	0.18
N	3/3d	34.37	36.70	2.33	36.59	38.14	1.55
O	2/3c,d	35.38	35.32	−0.06	36.29	36.53	0.24
P	3/3	34.18	35.70	1.52	34.84	35.23	0.39
Q	2/3c,e	36.01	Undetected	NA	35.61	38.90	3.29
R	3/3	33.65	35.05	1.40	35.01	37.74	2.73
S	3/3	33.72	35.40	1.68	35.45	39.67	4.22
T	3/3f	35.55	37.04	1.49	37.21	38.61	1.40
Aggregate datag	57/60 (95%)	34.50 (33.01–36.01)	35.20 (33.64–37.34)	0.97 (−0.92–2.63), 0.67	35.70 (33.86–37.21)	36.95 (34.87–38.90)	1.58 (−2.24–3.29), 1.80

^aEach positive specimen (n = 20) was pooled with four negative specimens. Each pool was prepared three times such that pools were prepared and tested in triplicate. NA, not applicable.

^bValues represent the means from three replicates unless otherwise noted.

^cN1 and N2 were undetected in one of three replicates.

^dN1 was undetected in one of three replicates. The pool would be deconvoluted for individual sample testing.

^eN1 was undetected in two of three replicates. Pools would be deconvoluted for individual sample testing.

^fN2 was undetected in two of three replicates. Pools would be deconvoluted for individual sample testing.

^gAggregate data are shown as the total number of PCR-positive pools/total number of pools tested (percent); mean (range); or mean (range), standard deviation.