title: Clinical outcomes of pyrazinamide-monoresistant Mycobacterium tuberculosis in Quebec.
abstract: BACKGROUND
  In Quebec, 6.2% of all tuberculosis (TB) isolates from Canadian-born patients are resistant to pyrazinamide (PZA) alone. The clinical significance of PZA-monoresistant (PZA(MR)) TB is unknown.
  
  
  METHODS
  Canadian-born patients with PZA(MR) TB diagnosed  between 1 January 1990 and 31 December 2000 and reported in a prior study were compared to randomly selected Canadian-born patients with fully susceptible isolates diagnosed within the same time period.
  
  
  RESULTS
  A total of 318 patients were eligible, of whom 40 (12.6%) had missing outcome  information. Mean total duration of treatment was respectively 9.0 and 8.9 months for those with PZA(MR) and pan-susceptible strains. Respectively 91% and 89% of PZA(MR) and pan-susceptible patients received at least 6 months of rifampin-containing treatment. Among 67 patients  with PZA(MR) TB, 51 (76%) were cured, 3 (4%) relapsed, none failed treatment, and 16 (24%) died within 6 months of diagnosis. Of 211 subjects with fully susceptible isolates, 181 (86%) were cured, 2 (1%) relapsed, 2 (1%) failed treatment, and 30 (14%) died within 6 months of diagnosis.  PZA monoresistance was associated with decreased odds of successful clinical outcomes compared with pan-susceptible TB (OR 0.4, 95%CI 0.2-0.8).
  
  
  CONCLUSIONS
  Patients with PZA(MR) TB had significantly worse clinical outcomes than patients with fully susceptible strains.
authors.affiliation: Respiratory Epidemiology and Clinical Research Unit, Montreal Chest Institute, McGill University Health Center, Montreal, Quebec, Canada.
authors.forename: D P
authors.initials: DP
authors.lastname: Yee
authors.forename: D
authors.initials: D
authors.lastname: Menzies
authors.forename: P
authors.initials: P
authors.lastname: Brassard
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000995:Antitubercular Agents / Q000494:pharmacology / Q000627:therapeutic use*; D015331:Cohort Studies; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000302:isolation & purification; D011718:Pyrazinamide / Q000494:pharmacology*; D011792:Quebec; D012008:Recurrence; D012189:Retrospective Studies; D012293:Rifampin / Q000627:therapeutic use; D016896:Treatment Outcome; D014376:Tuberculosis / Q000188:drug therapy* / Q000382:microbiology
chemical_list: D000995:Antitubercular Agents; D011718:Pyrazinamide; D012293:Rifampin