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. 2001 Dec;39(12):4506–4513. doi: 10.1128/JCM.39.12.4506-4513.2001

TABLE 3.

Sensitivities and specificities of WN virus NASBA assays compared to those of Vero cell culture, TaqMan assay, and standard RT-PCRa

Sample Quantity (no. of PFv) RT-PCR with 233-640 TaqMan assayb
NASBA-ECL assayc
NASBA-beacon assayd
CT Int. ECL units Int. Beacon (min) Int.
Titrated WN virus (NY99) seede
 WNV-1 100,000 POS 17.9 POS 1,653,417 POS 15.2 POS
 WNV-2 10,000 POS 20.9 POS 1,187,613 POS 16.6 POS
 WNV-3 1,000 POS 24.2 POS 1,810,790 POS 20.2 POS
 WNV-4 100 POS 27.8 POS 1,666,084 POS 22.8 POS
 WNV-5 10 POS 31.2 POS 1,211,426 POS 28.0 POS
 WNV-6 1 POS 34.1 POS 1,209,491 POS 31.7 POS
 WNV-7 0.1 NEG 36.8 POS 326,954 POS 35.6 POS
 WNV-8 0.01 NEG 45.0 NEG 5,782 POS 90.0 NEG
 WNV-9 0.001 NEG 45.0 NEG 110 NEG 90.0 NEG
 WNV-10 0.0001 NEG 45.0 NEG 91 NEG ND NEG
WN virus strains
 WNV-Romania-1996M ND POS 29.02 POS 313,605 POS 32.8 POS
 WNV-Egypt-1951 ND POS 25.54 POS 437,541 POS 19.0 POS
 WNV-Italy 1998 ND POS 23.82 POS 237,753 POS 18.1 POS
 WNV-Kenya 1998 ND POS 21.38 POS 226,175 POS 26.1 POS
 Kunjin ND POS 20.58 POS 109 NEG 90 NEG
Other viruses
 DEN-2 ND NEG 45 NEG 27 NEG 90 NEG
 YF ND NEG 45 NEG 8 NEG 90 NEG
 SLE ND NEG 45 NEG 1 NEG 90 NEG
 JE ND NEG 45 NEG 7 NEG 90 NEG
 MVE ND NEG 45 NEG 2 NEG 90 NEG
 EEE ND NEG 45 NEG 1 NEG 90 NEG
 WEE ND NEG 45 NEG 12 NEG 90 NEG
 POW ND NEG 45 NEG 29 NEG 90 NEG
 LAC ND NEG 45 NEG 1 NEG 90 NEG
a

Abbreviations: POS, positive; NEG, negative; Int., interpretation; ND, not determined; DEN-2, dengue virus type 2; YF, yellow fever virus, JE, Japanese encephalitis virus; MVE, Murrey Valley encephalitis virus; EEE, equine encephalitis virus; WEE, western equine encephalitis virus; POW, Powassan virus; LAC, La Crosse virus. 

b

A CT value of <37 was positive; for an explanation of TaqMan assay data interpretation, see Materials and Methods. 

c

NASBA-ECL assay units >300 are interpreted as positive. 

d

Values shown are the times at which fluorescence crosses the threshold; values <60 min are interpreted as positive. For a complete explanation of real-time NASBA-beacon assay data interpretation, see Materials and Methods. 

e

All TaqMan CT, NASBA-ECL, and NASBA-beacon assay values were calculated by averaging the values from samples tested in duplicate.