title: Global trends in resistance to antituberculosis drugs. World Health Organization-International Union against Tuberculosis and Lung Disease Working Group on Anti-Tuberculosis Drug Resistance Surveillance.
abstract: BACKGROUND
  Data on global trends in resistance to antituberculosis drugs are lacking.
  
  
  METHODS
  We expanded the survey conducted by the World Health Organization and the International Union against Tuberculosis and Lung Disease to assess trends in resistance to antituberculosis drugs in countries on six continents. We obtained data using standard protocols from ongoing surveillance or from surveys of representative samples of all patients with tuberculosis. The standard sampling techniques distinguished between new and previously treated patients, and laboratory performance was checked by means of an international program of quality assurance.
  
  
  RESULTS
  Between 1996 and 1999, patients in 58 geographic sites were surveyed; 28 sites provided data for at least two years. For patients with newly diagnosed tuberculosis, the frequency of resistance to at least one antituberculosis drug ranged from 1.7 percent in Uruguay to 36.9 percent in Estonia (median, 10.7 percent). The prevalence increased in Estonia, from 28.2 percent in 1994 to 36.9 percent in 1998 (P=0.01), and in Denmark, from 9.9 percent in 1995 to 13.1 percent in 1998 (P=0.04). The median prevalence of multidrug resistance among new cases of tuberculosis was only 1.0 percent, but the prevalence was much higherin Estonia (14.1 percent), Henan Province in China (10.8 percent), Latvia (9.0 percent), the Russian oblasts of Ivanovo (9.0 percent) and Tomsk (6.5 percent), Iran (5.0 percent), and Zhejiang Province in China (4.5 percent). There were significant decreases in multidrug resistance in France and the United States. In Estonia, the prevalence in all cases increased from 11.7 percent in 1994 to 18.1 percent in 1998 (P<0.001).
  
  
  CONCLUSIONS
  Multidrug-resistant tuberculosis continues to be a serious problem, particularly among some countries of eastern Europe. Our survey also identified areas with a high prevalence of multidrug-resistant tuberculosis in such countries as China and Iran.
authors.affiliation: Communicable Diseases Cluster, World Health Organization, Geneva, Switzerland. espinalm@who.int
authors.forename: M A
authors.initials: MA
authors.lastname: Espinal
authors.forename: A
authors.initials: A
authors.lastname: Laszlo
authors.forename: L
authors.initials: L
authors.lastname: Simonsen
authors.forename: F
authors.initials: F
authors.lastname: Boulahbal
authors.forename: S J
authors.initials: SJ
authors.lastname: Kim
authors.forename: A
authors.initials: A
authors.lastname: Reniero
authors.forename: S
authors.initials: S
authors.lastname: Hoffner
authors.forename: H L
authors.initials: HL
authors.lastname: Rieder
authors.forename: N
authors.initials: N
authors.lastname: Binkin
authors.forename: C
authors.initials: C
authors.lastname: Dye
authors.forename: R
authors.initials: R
authors.lastname: Williams
authors.forename: M C
authors.initials: MC
authors.lastname: Raviglione
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology / Q000627:therapeutic use; D003625:Data Collection; D018432:Drug Resistance, Multiple; D014943:Global Health; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000187:drug effects; D015995:Prevalence; D012494:Sampling Studies; D014376:Tuberculosis / Q000188:drug therapy*
chemical_list: D000995:Antitubercular Agents