TABLE 2.

Sensitivities and specificities of North American EEE virus NASBA, standard RT-PCR, TaqMan, and Vero cell culture assays^a

Sample	Quantity (PFU)	NASBAc		Standard RT-PCR	TaqMand
		ECL units	Int.		CT	Int.
Titrated EEE NJ/60 seed (New Jersey 1960)
EEE-1	770,000	1,086,839	POS	POS	11.7	POS
EEE-2	77,000	1,004,872	POS	POS	14.4	POS
EEE-3	7,700	918,511	POS	POS	17.7	POS
EEE-4	770	87,634	POS	POS	20.8	POS
EEE-5	77	647,862	POS	POS	23.8	POS
EEE-6	7.7	543,737	POS	POS	26.3	POS
EEE-7	0.77	550,841	POS	POS	30.2	POS
EEE-8	0.077	721,557	POS	EQUIVe	33.7	POS
EEE-9	0.0077	146	NEG	NEG	37.2	EQUIV
EEE-10	0.00077	163	NEG	NEG	45	NEG
EEE virus strains
EEE Michigan 1989	ND	255,654	POS	POS	14.9	POS
EEE New Jersey 1980	ND	10,894	POS	POS	14.3	POS
EEE Texas 1989	ND	91,898	POS	POS	15.1	POS
EEE Dominican Republic 1987	ND	254,396	POS	POS	14.5	POS
EEE Delaware 2001	ND	109,511	POS	POS	13.4	POS
EEE Virginia 2001 a	ND	107,749	POS	POS	14	POS
EEE Virginia 2001 b	ND	124,663	POS	POS	15.8	POS
EEE Virginia 2001 c	ND	113,366	POS	POS	14	POS
EEE Virginia 2001 d	ND	115,768	POS	POS	15.1	POS
EEE Virginia 2001 e	ND	53,367	POS	POS	16.2	POS
EEE Ecquador 1974b	ND	546	POS	NEG	43.3	NEG
EEE Brazil 1956b	ND	156	NEG	NEG	45	NEG
EEE Brazil 1976b	ND	169	NEG	NEG	45	NEG
EEE Panama 1981b	ND	167	NEG	NEG	45	NEG
Other viruses
WEE McMillan	ND	147	NEG	NEG	45	NEG
Highlands J B230	ND	171	NEG	NEG	45	NEG
VEE TC83	ND	142	NEG	NEG	45	NEG
LaCrosse Original	ND	147	NEG	NEG	45	NEG
Dengue-2 New Guinea	ND	126	NEG	NEG	45	NEG
Powassan LB	ND	135	NEG	NEG	45	NEG
Yellow Fever 17-D	ND	135	NEG	NEG	45	NEG

^aAbbreviations: POS, positive; NEG, negative; EQUIV, equivocal; ND, not determined; Int., interpretation.

^bEEE South American antigenic group strain.

^cNASBA ECL units of >300 are interpreted as positive.

^dTaqMan C_T values of ≤37 are interpreted as positive (Rn values not included).

^eEquivocal standard RT-PCR result determined by the presence of a faint DNA band.