TABLE 2.

Comparative sensitivities and specificities of the RT-LAMP and RT-PCR assay systems for detection of WN virus^a

Virus	Quantity (PFU)	RT-PCRb	RT-LAMP
			Agarose gel analysis	Real-time monitoring of turbidity
				Tp (min)	Interpretationb
WN virus strain NY99	10,000	Pos	Pos	17	Pos
	1,000	Pos	Pos	18	Pos
	100	Pos	Pos	19	Pos
	10	Pos	Pos	22	Pos
	1	Pos	Pos	25	Pos
	0.1	Neg	Pos	33	Pos
	0.01	Neg	Neg	NA	Neg
	0.001	Neg	Neg	NA	Neg
	0.0001	Neg	Neg	NA	Neg
	0	Neg	Neg	NA	Neg
WN virus strain Eg101	1	Pos	Pos	28	Pos
	0.1	Neg	Pos	37	Pos
	0.01	Neg	Neg	NA	Neg
JE virus	100,000	Neg	Neg	NA	Neg
DEN-2	100,000	Neg	Neg	NA	Neg
SLE virus	ND	Neg	Neg	NA	Neg

^aPos, positive; Neg, negative; NA, turbidity did not appear; ND, not determined.

^bPositive result by RT-PCR revealed 201-bp amplicon on 3% agarose gel analysis.

^cTp of ≤60 min is interpreted as positive by the real-time RT-LAMP method.