title: Prevalence of resistance to second-line tuberculosis drug among multidrug-resistant tuberculosis patients in Viet Nam, 2011.
abstract: BACKGROUND
  Extensively drug-resistant tuberculosis (XDR-TB) represents an emerging public health problem worldwide. According to the World Health Organization, an estimated 9.7% of multidrug-resistant TB (MDR-TB) cases are defined as XDR-TB globally. The objective of this study was to determine the prevalence of drug resistance to second-line TB drugs among MDR-TB cases detected in the Fourth National Anti-Tuberculosis Drug Resistance Survey in Viet Nam.
  
  
  METHODS
  Eighty clusters of TB cases were selected using a probability-proportion-to-size approach. To identify MDR-TB cases, drug susceptibility testing (DST) was performed for the four major first-line TB drugs. DST of second-line drugs (ofloxacin, amikacin, kanamycin, capreomycin) was performed on isolates from MDR-TB cases to identify pre-XDR and XDR cases.
  
  
  RESULTS
  A total of 1629 smear-positive TB cases were eligible for culture and DST. Of those, DST results for first-line drugs were available for 1312 cases, and 91 (6.9%) had MDR-TB. Second-line DST results were available for 84 of these cases. Of those, 15 cases (17.9%) had ofloxacin resistance and 6.0% were resistant to kanamycin and capreomycin. Five MDR-TB cases (6.0%) met the criteria of XDR-TB.
  
  
  CONCLUSIONS
  This survey provides the first estimates of the proportion of XDR-TB among MDR-TB cases in Viet Nam and provides important information for local policies regarding second-line DST. Local policies and programmes that are geared towards TB prevention, early diagnosis and treatment with effective regimens are of high importance.
authors: National Tuberculosis Control Programme Viet Nam, Hanoi, Viet Nam.; Centre for Operational Research, International Union Against Tuberculosis and Lung Disease, Paris, France.
authors: Hoa Binh
authors: HB
authors: Nguyen
authors: National Tuberculosis Control Programme Viet Nam, Hanoi, Viet Nam.; Viet Nam Association for Tuberculosis and Lung Disease, Hanoi, Viet Nam.
authors: Nhung Viet
authors: NV
authors: Nguyen
authors: Ministry of Health, Department of International Cooperation, Viet Nam .
authors: Huong Thi Giang
authors: HT
authors: Tran
authors: Hanoi Medical University, Hanoi, Viet Nam .
authors: Hai Viet
authors: HV
authors: Nguyen
authors: Hanoi School of Public Health, Hanoi, Viet Nam .
authors: Quyen Thi Tu
authors: QT
authors: Bui
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000995:Antitubercular Agents / Q000627:therapeutic use*; D003430:Cross-Sectional Studies; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects*; D054908:Extensively Drug-Resistant Tuberculosis / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000302:isolation & purification; D015995:Prevalence; D014744:Vietnam / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents