title: Transmission of MDR and XDR tuberculosis in Shanghai, China.
abstract: BACKGROUND
  Multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) are global health problems. We sought to determine the characteristics, prevalence, and relative frequency of transmission of MDR and XDR TB in Shanghai, one of the largest cities in Asia.
  
  
  METHODS
  TB is diagnosed in district TB hospitals in Shanghai, China. Drug susceptibility testing for first-line drugs was performed for all culture positive TB cases, and tests for second-line drugs were performed for MDR cases. VNTR-7 and VNTR-16 were used to genotype the strains, and prior treatment history and treatment outcomes were determined for each patient.
  
  
  RESULTS
  There were 4,379 culture positive TB cases diagnosed with drug susceptibility test results available during March 2004 through November 2007. 247 (5.6%) were infected with a MDR strain of M. tuberculosis and 11 (6.3%) of the 175 MDR patients whose isolate was tested for susceptibility to second-line drugs, were XDR. More than half of the patients with MDR and XDR were newly diagnosed and had no prior history of TB treatment. Nearly 57% of the patients with MDR were successfully treated.
  
  
  CONCLUSIONS
  Transmission of MDR and XDR strains is a serious problem in Shanghai. While a history of prior anti-TB treatment indicates which individuals may have acquired MDR or XDR TB, it does not accurately predict which TB patients have disease caused by transmission of MDR and XDR strains. Therefore, universal drug susceptibility testing is recommended for new and retreatment TB cases.
authors.affiliation: Department of TB Control, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhao
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.forename: Peng
authors.initials: P
authors.lastname: Xu
authors.forename: Xin
authors.initials: X
authors.lastname: Shen
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Gui
authors.forename: Lili
authors.initials: L
authors.lastname: Wang
authors.forename: Kathryn
authors.initials: K
authors.lastname: Deriemer
authors.forename: Jian
authors.initials: J
authors.lastname: Mei
authors.forename: Qian
authors.initials: Q
authors.lastname: Gao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002681:China; D024901:Drug Resistance, Multiple, Bacterial; D054908:Extensively Drug-Resistant Tuberculosis / Q000382:microbiology / Q000628:therapy / Q000635:transmission*; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000235:genetics; D016896:Treatment Outcome