Table 2.
Stool PCR sensitivity
| (A) Analysis by subject | ||||
| Fast DNA stool PCR | Tuberculosis cases (N = 16) | Healthy controls (N = 23) | Sensitivity | Specificity |
|
| ||||
| Fast PCR (+) | 6 | 0 | 38% | 100% |
| Fast PCR (−) | 10 | 23 | ||
|
| ||||
| Chelex stool PCR | Tuberculosis cases (N = 16) | Healthy controls (N = 23) | ||
|
| ||||
| Chelex PCR (+) | 5 | 0 | 31% | 100% |
| Chelex PCR (−) | 11 | 23 | ||
|
(B) Analysis by specimen | ||||
| Stool and culture samples from cases (N = 28) |
Healthy control samples (N = 28) |
Sensitivity | Specificity | |
|
| ||||
| Fast (+) stool PCR | 9 | 0 | 31% | 100% |
| Fast (−) stool PCR | 19 | 28 | ||
| Chelex (+) stool PCR | 6 | 0 | 21% | 100% |
| Chelex (−) stool PCR | 22 | 28 | ||
| Gastric aspirate culture (+) | 20 | Not done | 71% | NA |
| Gastric aspirate culture (−) | 8 | Not done | ||
| Nasopharyngeal aspirate culture (+) | 9 (missing 1) | 28 | 31% | 100% |
| Nasopharyngeal aspirate culture (−) | 18 | 28 | ||
The sensitivity and specificity of stool PCR for the detection of M. tuberculosis is shown, analyzed by DNA extraction diagnostic method amongst children with at least one positive TB culture and from healthy control children. (A) Analysis by subject and (B) analysis by specimen: sensitivity and specificity of stool PCR of gastric aspirate culture and nasopharyngeal culture for detection of M. tuberculosis.