Table 3. Sputum culture and phenotypic drug resistance of 243 Xpert rifampicin-resistant TB patients.
| Test | n (%) |
|---|---|
| Sputum culture (n = 243) | |
| Positive | 162 (66.7) |
| Negative | 57 (23.5) |
| Non-tuberculous mycobacteria | 16 (6.6) |
| Contaminated | 8 (3.3) |
| Individual drug-resistance (n = 162) | |
| Rifampicin | 145(89.5) |
| Isoniazid | 128 (79.0) |
| Ethambutol | 95 (58.6) |
| Streptomycin | 67 (41.4) |
| Kanamycin# | 8 (4.9) |
| Amikacin# | 4 (2.5) |
| Ofloxacin# | 33 (20.4) |
| Drug resistance by definition (n = 162) | |
| MDR-TB* | 107 (66.0) |
| Pre-XDR TB** | 28 (17.3) |
| Pre-XDR with injectables resistance | 2 (1.2) |
| Pre-XDR with fluoroquinolone resistance | 26 (16.1) |
| XDR-TB*** | 4 (2.5) |
| RIF monoresistance | 6 (3.7) |
| INH monoresistance | 3 (1.9) |
| Monoresistancea | 1 (0.6) |
| Polyresistanceb | 1 (0.6) |
| RIF-sensitive | 12 (7.4) |
#Missing data for two patients.
*Multidrug-resistant TB (MDR-TB): resistant to at least isoniazid and rifampicin.
**Pre-XDR TB: resistant to isoniazid and rifampicin and either a fluoroquinolone and second-line anti-TB injectable drugs, but not both.
***Extensively drug-resistant TB (XDR-TB): resistant to isoniazid and rifampicin (as well as any fluoroquinolone and at least one of three second-line anti-TB injectable drugs (amikacin, kanamycin and capreomycin.
aMonoresistance: resistance to one first-line anti-TB drug only.
bPolyresistance: resistance to more than one first-line anti-TB drug, other than both isoniazid and rifampicin.[8]