Table 3. Patterns of second-line drug resistance in rifampin- and isoniazid-resistant Mycobacterium tuberculosis isolates, Swaziland, 2009–2010*.
| Resistance pattern | No. (%) isolates resistant to isoniazid or rifampin,† n = 60 | No. (%) isolates from case-patients with MDR TB, n = 122 |
|---|---|---|
| No resistance to second-line drugs | 54 (90.0) | 72 (49.2) |
| Any resistance | 6 (10.0) | 62 (50.8) |
| Ethionamide | 6 (10.0) | 58 (47.5) |
| Ofloxacin | 0 | 10 (8.2) |
| p-aminosalicylic acid | 0 | 0 |
| Cycloserine | 0 | 0 |
| Amikacin | 0 | 2 (1.6) |
| Capreomycin | 0 | 3 (2.5) |
| Specific resistance patterns | ||
| Ethionamide | 6 (10.0) | 50 (41.0) |
| Ethionamide + ofloxacin | 0 | 6 (4.9) |
| Ethionamide + amikacin + capreomycin | 0 | 1 (0.8) |
| Ethionamide + ofloxacin + amikacin + capreomycin | 0 | 1 (0.8) |
| Ofloxacin | 0 | 3 (2.5) |
| Capreomycin | 0 | 1 (0.8) |
| XDR | 0 | 1 (0.8) |
*MDR, multidrug resistant; TB, tuberculosis; XDR, extensively drug resistant. †Isolates from MDR TB patients excluded.