Volume 10, Number 5—May 2004
Research
Laboratory Diagnosis of SARS
Paul K.S. Chan*
, Wing-Kin To†, King-Cheung Ng*, Rebecca K. Y. Lam*, Tak-Keung Ng†, Rickjason C. W. Chan* , Alan Wu*, Wai-Cho Yu†, Nelson Lee*, David S. C. Hui*, Sik-To Lai†, Ellis K. L. Hon*, Chi-Kong Li*, Joseph J. Y. Sung*, and John S. Tam*
, Wing-Kin To†, King-Cheung Ng*, Rebecca K. Y. Lam*, Tak-Keung Ng†, Rickjason C. W. Chan* , Alan Wu*, Wai-Cho Yu†, Nelson Lee*, David S. C. Hui*, Sik-To Lai†, Ellis K. L. Hon*, Chi-Kong Li*, Joseph J. Y. Sung*, and John S. Tam*Table 3
Comparison on positive rates of RT-PCR and virus isolationa
| Specimen type (no.) | No. (%) of specimens tested positiveb |
Isolation/RT-PCR indexc | |
|---|---|---|---|
| RT-PCR | Virus isolation | ||
| Pooled throat and nasal swab (30) |
8 (26.7) |
4 (13.3) |
0.50 |
| Tracheal aspirate (13) |
6 (46.2) |
2 (15.4) |
0.33 |
| Nasopharyngeal aspirate (183) |
52 (28.4) |
14 (7.7) |
0.27 |
| Throat swab (58) |
11 (19.0) |
2 (3.4) |
0.18 |
| Nasal swab (56) |
14 (25.0) |
2 (3.6) |
0.14 |
| Urine (296) |
14 (4.7) |
2 (0.7) |
0.14 |
| Throat washing (218) |
17 (7.8) |
1 (0.5) |
0.06 |
| Stool (262) |
70 (26.7) |
2 (0.8) |
0.03 |
| Rectal swab (56) | 12 (21.4) | 0 (0) | 0 |
aRT-PCR, reverse transcription–polymerase chain reaction.
bOnly specimens tested by both RT-PCR and virus isolation are included.
cNo. of isolation-positive specimens per RT-PCR-positive specimen.
