TABLE 1.
Concordance between the test antigens and the pooled in-house antigens using culture-positive seraa
| Isolate from which the antigen was derived (country of origin) | No. (%) of serum samples for which the titer was:
|
No. (%) of results that wered:
|
r (CI)e | Pe | ||||
|---|---|---|---|---|---|---|---|---|
| Sameb | ±1 dilutionc | ±2 dilutionsc | ±3 or more dilutionsc | Concordant | Discordant | |||
| B. pseudomallei NCTC 13178 (Australia) | 9 (36) | 10 (40) | 3 (12) | 1 (4) | 23 (92) | 2 (8) | 0.8135 (0.6088-0.9167) | <0.0001 |
| B. pseudomallei 145 (Papua New Guinea) | 9 (36) | 8 (32) | 5 (20) | 1 (4) | 23 (92) | 2 (8) | 0.8506 (0.6795-0.9340) | <0.0001 |
| B. pseudomallei 148 (Sri Lanka) | 8 (32) | 11 (44) | 1 (4) | 4 (16) | 24 (96) | 1 (4) | 0.7690 (0.5281-0.8953) | <0.0001 |
| B. thailandensis | 5 (20) | 4 (16) | 5 (20) | 8 (32) | 22 (88) | 3 (12) | 0.1802 (−0.2432-0.5469) | <0.3887 |
The number of serum samples was 25. The range of titers was from 1:10 to more than 1:5,120. CI, confidence interval.
Concordance with the in-house IHA implies that an identical IHA titer was obtained using the antigen named.
Concordance within ±1, ±2, or ±3 (or more) dilutions implies that the IHA titer obtained using the antigen named was either above or below the titer obtained in the in-house IHA by that factor.
A discordant result implies that the IHA result obtained using the antigen named was negative, while the in-house test result was positive. Sera tested using the B. cepacia antigen were uniformly negative.
For concordant results, Spearman rank correlation was carried out to obtain r and P values.