Worldwide emergence of extensively drug-resistant tuberculosis

Emerg Infect Dis. 2007 Mar;13(3):380-7. doi: 10.3201/eid1303.061400.


Mycobacterium tuberculosis strains that are resistant to an increasing number of second-line drugs used to treat multidrug-resistant tuberculosis (MDR TB) are becoming a threat to public health worldwide. We surveyed the Network of Supranational Reference Laboratories for M. tuberculosis isolates that were resistant to second-line anti-TB drugs during 2000-2004. We defined extensively drug-resistant TB (XDR TB) as MDR TB with further resistance to > or = 3 of the 6 classes of second-line drugs. Of 23 eligible laboratories, 14 (61%) contributed data on 17,690 isolates, which reflected drug susceptibility results from 48 countries. Of 3,520 (19.9%) MDR TB isolates, 347 (9.9%) met criteria for XDR TB. Further investigation of population-based trends and expanded efforts to prevent drug resistance and effectively treat patients with MDR TB are crucial for protection of public health and control of TB.

MeSH terms

  • Antitubercular Agents / pharmacology*
  • Communicable Disease Control
  • Global Health*
  • Humans
  • Laboratories
  • Mycobacterium tuberculosis / drug effects*
  • Sentinel Surveillance*
  • Tuberculosis / drug therapy
  • Tuberculosis / microbiology
  • Tuberculosis / prevention & control*
  • Tuberculosis, Multidrug-Resistant


  • Antitubercular Agents