Table 2– Resistance to anti-tuberculosis drugs by multidrug-resistant tuberculosis (MDR-TB) patient group
MDR-TB onlyMDR-TB +INJrMDR-TB +FQrXDR-TBTotal MDR-TB cases
Cases n476311304264056724
Resistance
 First-line drugs
  Pyrazinamide1052 (41)556 (70)234 (58)211 (69)2053 (50)
  Ethambutol1524 (51)845 (76)296 (74)295 (81)2960 (61)
 Fluoroquinolones#00426 (100)405 (100)831 (12)
 Injectable drugs
  Streptomycin1534 (51)960 (86)226 (53)291 (78)3011 (61)
  Amikacin/kanamycin01042 (92)0383 (95)1425 (21)
  Capreomycin0399 (42)0104 (38)503 (16)
 Amikacin/kanamycin and capreomycin0311 (33)082 (30)393 (13)
 Amikacin/kanamycin and capreomycin and streptomycin0295 (31)068 (25)363 (12)
 Group 4 drugs
  Ethionamide/protionamide528 (19)401 (41)194 (48)212 (59)1335 (29)
  Cycloserine/terizidone125 (4)56 (5)76 (18)89 (24)346 (7)
  p-aminosalicylic acid391 (14)281 (31)125 (31)127 (43)924 (21)
TB drugs tested+7.9±3.010.0±1.310.2±0.99.6±1.78.5±2.1
Total number of TB drugs to which strain was resistant§
 22259 (47)0002259 (34)
 3947 (20)15 (1)19 (4)0981 (15)
 4784 (16)100 (9)66 (15)4 (1)954 (14)
 5513 (11)331 (29)101 (24)32 (8)977 (15)
 6209 (4)296 (26)118 (28)108 (27)731 (11)
 742 (1)221 (20)89 (21)105 (26)457 (7)
 89 (0.2)128 (11)25 (6)75 (19)237 (4)
 9037 (3)8 (2)46 (11)91 (1)
 ≥1002 (0.2)035 (9)37 (0.3)
  • Data are presented as n, n (%) or mean±sd. Drug-susceptibility test results for Group 5 drugs were available from very few centres and were not analysed. n (%) data are presented for the number of cases whose isolate was tested to that specific drug. All cases were tested for susceptibility to at least one fluoroquinolone (FQ) and one second-line injectable drug, but not all the other drugs. #: Most centres tested only for resistance to ofloxacin. Very few centres also tested for resistance to later-generation FQs (results of these tests are not shown). By definition, two patient groups were susceptible to FQ. : Resistance to amikacin or kanamycin combined. Most centres tested for susceptibility to only one of these two drugs and considered them cross-resistant. +: Includes tests to isoniazid and rifampin, as well as to FQs and second-line injectable drugs (performed in all cases). §: In addition to isoniazid and rifampin, to which all patients were resistant, being MDR-TB. MDR-TB: multidrug-resistant tuberculosis (resistance to at least isoniazid and rifampicin); MDR-TB only: MDR-TB, but susceptible to FQs, amikacin/kanamycin and capreomycin (at least one second-line injectable drug tested); MDR-TB+INJr: MDR-TB plus resistance to amikacin/kanamycin and/or capreomycin, but susceptible to FQs; MDR-TB+FQr: MDR-TB plus resistance to any FQ, but susceptible to amikacin/kanamycin and/or capreomycin (at least one second-line injectable drug tested); XDR-TB: extensively drug-resistant tuberculosis (MDR-TB plus resistance to any FQ and any second-line injectable drug (amikacin/kanamycin and/or capreomycin)).