TABLE 2.
Comparison of the sensitivity and specificity of NPA and NS specimens for the detection of respiratory viruses by IF, culture, and PCR
| Virus (no. of samples positivea by “gold standard”) and test | NPA
|
NS
|
P valueb | P valuec | ||
|---|---|---|---|---|---|---|
| Sensitivity (95% CI)d | Specificity (95% CI) | Sensitivity (95% CI) | Specificity (95% CI) | |||
| Adenovirus (28) | ||||||
| IF | 0.36 (0.19-0.56) | 1.00 (0.99-1.00) | 0.36 (0.19-0.56) | 1.00 (0.99-1.00) | 0.999 | 0.999 |
| Culture | 0.89 (0.72-0.98) | 1.00 (0.99-1.00) | 0.89 (0.72-0.98) | 1.00 (0.99-1.00) | 0.999 | 0.999 |
| PCR | 0.86 (0.67-0.96) | 1.00 (0.99-1.00) | 0.71 (0.51-0.87) | 1.00 (0.99-1.00) | 0.191 | 0.317 |
| Influenza A virus (32) | ||||||
| IF | 0.69 (0.50-0.84) | 1.00 (0.99-1.00) | 0.50 (0.32-0.68) | 1.00 (0.99-1.00) | 0.124 | 0.999 |
| Culture | 0.78 (0.60-0.91) | 1.00 (0.99-1.00) | 0.81 (0.64-0.93) | 1.00 (0.99-1.00) | 0.757 | 0.999 |
| PCR | 0.88 (0.71-0.96) | 1.00 (0.98-1.00) | 0.84 (0.67-0.95) | 0.99 (0.97-1.00) | 0.719 | 0.155 |
| Influenza B virus (16) | ||||||
| IF | 0.69 (0.41-0.89) | 1.00 (0.99-1.00) | 0.19 (0.04-0.46) | 1.00 (0.99-1.00) | 0.003 | 0.999 |
| Culture | 0.88 (0.62-0.98) | 1.00 (0.99-1.00) | 0.75 (0.48-0.93) | 1.00 (0.99-1.00) | 0.367 | 0.999 |
| PCR | 1.00 (0.79-1.00) | 1.00 (0.99-1.00) | 0.88 (0.62-0.98) | 1.00 (0.98-1.00) | 0.151 | 0.157 |
| Parainfluenza virus (41) | ||||||
| IF | 0.59 (0.42-0.74) | 1.00 (0.99-1.00) | 0.41 (0.26-0.58) | 1.00 (0.99-1.00) | 0.121 | 0.999 |
| Culture | 0.71 (0.54-0.84) | 1.00 (0.99-1.00) | 0.49 (0.33-0.65) | 1.00 (0.99-1.00) | 0.040 | 0.999 |
| PCR | 0.95 (0.83-0.99) | 0.98 (0.97-0.99) | 0.95 (0.83-0.99) | 1.00 (0.99-1.00) | 0.999 | 0.033 |
| RSV (43) | ||||||
| IF | 0.93 (0.81-0.99) | 1.00 (0.99-1.00) | 0.70 (0.54-0.83) | 1.00 (0.98-1.00) | 0.005 | 0.563 |
| Culture | 0.88 (0.75-0.96) | 1.00 (0.99-1.00) | 0.65 (0.49-0.79) | 1.00 (0.99-1.00) | 0.001 | 0.999 |
| PCR | 0.88 (0.75-0.96) | 1.00 (0.99-1.00) | 0.67 (0.51-0.81) | 1.00 (0.99-1.00) | 0.018 | 0.317 |
| Any of above (160) | ||||||
| IF | 0.67 (0.59-0.74) | 1.00 (0.98-1.00) | 0.48 (0.40-0.56) | 0.99 (0.98-1.00) | <0.001 | 0.563 |
| Culture | 0.82 (0.75-0.88) | 1.00 (0.99-1.00) | 0.69 (0.62-0.76) | 1.00 (0.99-1.00) | <0.009 | 0.999 |
| PCR | 0.91 (0.86-0.95) | 0.97 (0.95-0.99) | 0.81 (0.74-0.87) | 0.97 (0.95-0.99) | 0.009 | 0.806 |
a
A patient was considered to have a viral infection if (i) the virus was isolated in cell culture from either an NPA or an NS specimen and/or (ii) any specimen was positive at least by the other two methods and/or (iii) both specimens were positive by any method.
b
P value for the comparison of sensitivity between NPA and NS for detection of respiratory viruses.
c
P value for the comparison of specificity between NPA and NS for detection of respiratory viruses.
d
CI, confidence interval.