Table 2.
Sensitivity of the different diagnostic assays for all patients with tuberculosis and for those stratified by CD4 cell count
|
Sputum AFB |
TB ELISA |
Determine TB-LAM |
Determine TB-LAM and sputum AFB |
Xpert MTB/RIF (1 sample) |
Determine TB-LAM and Xpert MTB/RIF |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Positive | Sensitivity | Positive | Sensitivity | Positive | Sensitivity | Positive | Sensitivity | Positive | Sensitivity | Positive | Sensitivity | |
| All (n=85) | 24 | 28·2% (19·0–39·0) | 23 | 27·1% (18·0–37·8) | 24 | 28·2% (19·0–39·0) | 37 | 43·5% (32·8–54·7) | 49 | 57·6% (46·4–68·3) | 52 | 61·2% (50·0–71·6) |
| <50 cells per μL (n=18) | 6 | 33·3% (13·3–59·0) | 11 | 61·1% (35·7–82·7) | 12 | 66·7% (41·0–86·7) | 13 | 72·2% (46·5–90·3) | 13 | 72·2% (46·5–90·3) | 15 | 83·3% (58·6–96·4) |
| <100 cells per μL (n=29) | 10 | 34·5% (17·9–54·3) | 14 | 48·3% (29·4–67·5) | 15 | 51·7% (32·5–70·6) | 19 | 65·5% (45·7–82·1) | 22 | 75·9% (56·5–89·7) | 24 | 82·8% (64·2–94·2) |
| <150 cells per μL (n=46) | 16 | 34·8% (21·4–50·2) | 20 | 43·5% (28·9–58·9) | 21 | 45·7% (30·9–61·0) | 27 | 58·7% (43·2–73·0) | 33 | 71·7% (56·5–84·0) | 35 | 76·1% (61·2–87·4) |
| <200 cells per μL (n=59) | 18 | 30·5% (19·2–43·9) | 21 | 35·6% (23·6–49·1) | 23 | 39·0% (26·5–52·6) | 31 | 52·5% (39·1–65·7) | 37 | 62·7% (49·1–75·0) | 40 | 67·8% (54·4–79·4) |
| ≥200 cells per μL (n=25) | 6 | 24·0% (9·4–45·1) | 2 | 8·0% (1·0–26·0) | 1 | 4·0% (0·1–20·4) | 6 | 24·0% (9·4–45·1) | 11 | 44·0% (24·4–65·1) | 11 | 44·0% (24·4–65·1) |
84 patients stratified by CD4 cell count. Data are number and sensitivity (95% CI). AFB=acid-fast bacilli. LAM=lipoarabinomannan. MTB/RIF=Mycobacterium tuberculosis/rifampicin.