TABLE 3.

Serial dilutions of ZIKV stock (2.18 × 10⁹ GCE/ml) in serum and urine for limits of detection

Dilution factor	Presumptive GCE/ml	Serum			Urine
		No. of samples	No. (%) positive	95% CI	No. of samples	No. (%) positive	95% CI
1:100	21,800,000	1	1 (100)	2.5–100	1	1 (100)	2.5–100
1:1,000	2,180,000	1	1 (100)	2.5–100	1	1 (100)	2.5–100
1:10,000	218,000	1	1 (100)	2.5–100	1	1 (100)	2.5–100
1:100,000	21,800	1	1 (100)	2.5–100	1	1 (100)	2.5–100
1:1,000,000	2,180	1	1 (100)	2.5–100	1	1 (100)	2.5–100
1:10,000,000	218	20	20 (100)	83–100	20	20 (100)	83–100
1:100,000,000	21.8	50	50 (100)	93–100	50	49 (98)	89–100
1:200,000,000	10.9	50	46 (92)	81–98	50	42 (84)	71–93
1:1,000,000,000	2.18	50	33 (66)	51–79	50	12 (24)	13–38
1:2,000,000,000	1.09	50	9 (18)	9–31	50	3 (6)	1–17
1:20,000,000,000	0.109	50	1 (2)	0.1–11	50	0 (0)	0–7
1:200,000,000,000	0.0109	30	0 (0)	0–12	30	0 (0)	0–12

CI, confidence interval.