Table 3. Second-line–drug resistance patterns for multidrug-resistant Mycobacterium tuberculosis isolates, 2000–2004*†‡.
| Pattern | No. tested | No. (%) resistant |
|---|---|---|
| Any resistance (total) | 3,520 | 1,542 (43.8) |
| Aminoglycosides (AG)§ | 3,442 | 630 (18.3) |
| Capreomycin (CM) | 2,743 | 279 (10.2) |
| Fluoroquinolones (FQ) | 3,492 | 673 (19.3) |
| Thioamides (TA) | 3,132 | 605 (19.3) |
| Cycloserine (CS) | 2,615 | 141 (5.4) |
| Para-aminosalicylic acid (PAS) | 2,860 | 450 (15.7) |
| Extensively drug-resistant TB (XDR-TB, total)¶ | 3,520 | 347 (9.9) |
| AG + CM + FQ | 2,656 | 90 (3.4) |
| AG + CM + TA | 2,498 | 77 (3.1) |
| CM + FQ + TA | 260 | 50 (19.2) |
| AG + FQ + TA | 3,040 | 102 (3.4) |
| AG + FQ + CS | 139 | 39 (28.1) |
| FQ + TA + PAS | 2,505 | 94 (3.8) |
*Tested for ≥3 second-line drug classes; SRLs, Supranational Reference Laboratories. †Not all isolates were tested for each second-line drug class (with the exception of the Republic of Korea SRL), so results are reported as a proportion of isolates tested to the specified class of drugs. For combination resistance patterns, results are reported as a proportion of isolates tested to all of the classes of drugs in the specific combination. ‡Cells are not mutually exclusive. §Other than streptomycin (e.g., kanamycin, amikacin). ¶XDR-TB, extensively drug-resistant tuberculosis, i.e., multidrug-resistant tuberculosis (resistant to at least isoniazid and rifampin) with additional resistance to ≥3 classes of second-line drugs.