TABLE 2.
Individual Xpert M. tuberculosis results by smear gradea
| Smear grade | No. (%) of participants with the following Xpert semiquantitative M. tuberculosis level: |
|||||
|---|---|---|---|---|---|---|
| Negative | Very low | Low | Medium | High | Total | |
| Negative | 540 (98) | 14 (88) | 15 (100) | 12 (38) | 3 (8) | 584 (90) |
| Scanty | 5 (1) | 1 (6) | 0 (0) | 3 (9) | 4 (11) | 13 (2) |
| 1+ | 4 (1) | 0 (0) | 0 (0) | 7 (22) | 8 (22) | 19 (3) |
| 2+ | 0 (0) | 0 (0) | 0 (0) | 8 (25) | 11 (31) | 19 (3) |
| 3+ | 0 (0) | 1 (6) | 0 (0) | 2 (6) | 10 (28) | 13 (2) |
| Total | 549 (100) | 16 (100) | 15 (100) | 32 (100) | 36 (100) | 648 (100) |
Only cases that had both a valid Xpert M. tuberculosis result and a smear microscopy result are included. Specifically, data for only 99 of 115 individual Xpert M. tuberculosis-positive cases in the study are included here, as 14 did not have an available smear result, and 2 individuals with smear-positive/Xpert-positive results were missing Xpert semiquantitative M. tuberculosis level data. Smear grading was as follows: scanty, 1 to 9 acid-fast bacilli per 100 immersion fields; 1+, 10 to 99 acid-fast bacilli per 100 immersion fields; 2+, 1 to 10 acid-fast bacilli per immersion field; and 3+, >10 acid-fast bacilli per immersion field. Xpert semiquantitative M. tuberculosis levels were classified as follows: very low, CT value of >28; low, CT value of 22 to 28; medium, CT value of 16 to 22; and high, CT value of <16.