TABLE 2.
Comparison of reports of the accuracy of the Binax NOW RSV antigen immunoassay
| Reference | Yr | % Sensitivity | % Specificity | Age when tested | Total no. of tests | No. antigen positive | Specimen(s)a | Reference test(s) |
|---|---|---|---|---|---|---|---|---|
| 31 | 2004 | 87.0 | 94.0 | 6.9 mo | 306 | Not available | NPA | DFA |
| 34 | 2004 | 89.0 | 100.0 | 6 days to adultb | 118 | 31 | NPA, NPW, N | Culture |
| 47 | 2004 | 94.6 | 88.5 | <17.0 yrc | 84 | 35 | NPW | Shell vial |
| 2 | 2004 | 89.2 | 100.0 | <18.0 yrd | 310e | 102 | NPWf | DFA, PCR, cultureg |
| 22 | 2006 | 87.5 | 100.0 | <5.0 yr | 91 | 14 | NPA | DFA, culture |
| 6 | 2006 | 73.0 | 100.0 | <18.0 yr | 130 | 33 | NPAf | DFA, shell vial |
| 10 | 2007 | 81.0 | 93.0 | Not availableh | 14,756 | 794 | NWi | Culture |
| This study | 2008 | 84.0 | 99.0 | Median, 1.5 yrj | 256 | 92 | NPA, NPSj | Culture, PCR |
NPA is nasopharyngeal aspirate, NW is nasal wash, NPS is nasopharyngeal swab, N is nasal, and NPW is nasopharyngeal wash.
71% of the specimens were from persons <32 months old.
81% of the specimens were from persons <3 years old.
80% of the specimens were from persons <12 months old.
Specimens for antigen immunoassays were initially frozen.
Specimens were in 3 ml of viral transport medium.
Viral culture was performed after shipment to referral laboratory with average 36-h delay before setup.
6.5% of the specimens were from persons <1 month old.
96.2% of the specimens were nasal washes.
Data from this study (the median age of RSV-positive patients was 6.2 months) include the testing of 38 nasopharyngeal swab samples, of which 5 were RSV positive.