title: Incidence and risk factors for extensively drug-resistant tuberculosis in Delhi region.
abstract: BACKGROUND
  India with a major burden of multidrug-resistant tuberculosis (MDR-TB) does not have national level data on this hazardous disease. Since 2006, emergence of extensively drug-resistant TB (XDR-TB) is considered a serious threat to global TB control. This study highlights the demographic and clinical risk factors associated with XDR-TB in Delhi.
  
  
  METHODS
  The study was conducted during April 2007 to May 2010. Six hundred eleven MDR-TB suspects were enrolled from four tertiary care hospitals, treating TB patients in Delhi and the demographic details recorded. Sputum samples were cultured using rapid, automated liquid culture system (MGIT 960). Drug susceptibility testing (DST) for Rifampicin (RIF) and Isoniazid (INH) was performed for all positive M. tuberculosis (M.tb) cultures. All MDR-TB isolates were tested for sensitivity to second-line drugs [Amikacin (AMK), Capreomycin (CAP), Ofloxacin (OFX), Ethionamide (ETA)].
  
  
  RESULTS
  Of 611, 483 patients were infected with MDR M. tuberculosis (M.tb) strains. Eighteen MDR-TB isolates (3.7%) were XDR M.tb strains. Family history of TB (p 0.045), socioeconomic status (p 0.013), concomitant illness (p 0.001) and previous intake of 2(nd) line injectable drugs (p 0.001) were significantly associated with occurrence of XDR-TB. Only two of the patients enrolled were HIV seropositive, but had a negative culture for M. tuberculosis. 56/483 isolates were pre-XDR M. tuberculosis, though the occurrence of pre-XDR-TB did not show any significant demographical associations.
  
  
  CONCLUSIONS
  The actual incidence and prevalence rate of XDR-TB in India is not available, although some scattered data is available. This study raises a concern about existence of XDR-TB in India, though small, signaling a need to strengthen the TB control program for early diagnosis of both tuberculosis and drug resistance in order to break the chains of transmission.
authors: Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India.
authors: Chhavi
authors: C
authors: Porwal
authors: Amit
authors: A
authors: Kaushik
authors: Nayani
authors: N
authors: Makkar
authors: Jayant N
authors: JN
authors: Banavaliker
authors: Mahmud
authors: M
authors: Hanif
authors: Rupak
authors: R
authors: Singla
authors: Anuj K
authors: AK
authors: Bhatnagar
authors: Digambar
authors: D
authors: Behera
authors: Jitendra Nath
authors: JN
authors: Pande
authors: Urvashi B
authors: UB
authors: Singh
mesh_terms: D000328:Adult; D000583:Amikacin / Q000494:pharmacology / Q000627:therapeutic use; D000995:Antitubercular Agents / Q000494:pharmacology / Q000627:therapeutic use*; D002207:Capreomycin / Q000494:pharmacology / Q000627:therapeutic use; D005000:Ethionamide / Q000494:pharmacology / Q000627:therapeutic use; D054908:Extensively Drug-Resistant Tuberculosis / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D006801:Humans; D015994:Incidence; D007194:India / Q000453:epidemiology; D007538:Isoniazid / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D015242:Ofloxacin / Q000494:pharmacology / Q000627:therapeutic use; D015995:Prevalence; D012293:Rifampin / Q000494:pharmacology / Q000627:therapeutic use; D012307:Risk Factors; D013183:Sputum / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology
chemical_list: D000995:Antitubercular Agents; D002207:Capreomycin; D000583:Amikacin; D015242:Ofloxacin; D005000:Ethionamide; D007538:Isoniazid; D012293:Rifampin
references: Int J Tuberc Lung Dis. 2008 Jan;12(1):99-104
references: 18173885
references: J Clin Microbiol. 2006 Mar;44(3):688-92
references: 16517840
references: J Clin Microbiol. 2008 Dec;46(12):3952-6
references: 18945838
references: Clin Infect Dis. 2008 Aug 15;47(4):450-7
references: 18616396
references: J Clin Microbiol. 2011 Apr;49(4):1588-90
references: 21289142
references: Lancet Infect Dis. 2009 Jan;9(1):19-30
references: 18990610
references: J Clin Microbiol. 2009 Nov;47(11):3630-4
references: 19741086
references: Int J Tuberc Lung Dis. 2010 Feb;14(2):243-6
references: 20074419
references: AIDS. 2007 Nov 12;21(17):2345-7
references: 18090285
references: N Engl J Med. 2007 Feb 15;356(7):656-9
references: 17301295
references: Emerg Infect Dis. 2007 Sep;13(9):1429-31
references: 18252133
references: Clin Infect Dis. 2009 Mar 1;48(5):e50-2
references: 19191632
references: Eur Respir J. 2007 Mar;29(3):423-7
references: 17329486
references: PLoS One. 2010 Mar 04;5(3):e9527
references: 20209106
references: Lancet. 2012 Oct 20;380(9851):1406-17
references: 22938757
references: Indian J Med Res. 2009 Oct;130(4):392-5
references: 19942741
references: J Biosci. 2008 Nov;33(4):605-16
references: 19208985
references: PLoS Med. 2007 Jan;4(1):e50
references: 17253901
references: Antimicrob Agents Chemother. 2005 Aug;49(8):3192-7
references: 16048924
references: Wkly Epidemiol Rec. 2006 Nov 10;81(45):430-2
references: 17096498
references: Int J Tuberc Lung Dis. 2008 Dec;12(12):1449-55
references: 19017456
references: Clin Infect Dis. 2008 Jan 1;46(1):42-9
references: 18171212
references: Antimicrob Agents Chemother. 2010 Nov;54(11):4789-93
references: 20713679