title: Efficacy of control measures in preventing nosocomial transmission of multidrug-resistant tuberculosis to patients and health care workers.
abstract: OBJECTIVE
  To assess the efficacy of control measures in decreasing nosocomial transmission of multidrug-resistant tuberculosis.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  A teaching hospital in New York City.
  
  
  METHODS
  40 patients hospitalized with multidrug-resistant tuberculosis (case-patients) and health care workers receiving tuberculin skin testing.
  
  
  METHODS
  Centers for Disease Control and Prevention (CDC) 1990 guidelines for preventing transmission of tuberculosis, including 1) prompt isolation and treatment of patients with tuberculosis; 2) rapid diagnostic techniques for processing Mycobacterium tuberculosis specimens; 3) negative-pressure isolation rooms; and 4) molded surgical masks for health care workers.
  
  
  METHODS
  Proportion of case-patients with nosocomially acquired tuberculosis and rate of tuberculin skin test conversion among health care workers before and after implementation of control measures.
  
  
  RESULTS
  The proportion of patients with multidrug-resistant strains of M. tuberculosis decreased after the interventions (10 of 70 [14%] compared with 30 of 95 [32%] patients before the intervention; relative risk [RR], 0.5; 95% CI, 0.2 to 0.9). Before onset of multidrug-resistant tuberculosis, case-patients in the intervention period were as likely to be hospitalized on high-risk wards containing patients with tuberculosis (4 of 10 compared with 17 of 30 patients; RR, 0.7; P = 0.5) but were less likely to be exposed to another case-patient with tuberculosis (1 of 10 compared with 20 of 30 patients; RR, 0.2; P = 0.003). Tuberculin skin test conversion rates for health care workers assigned to wards housing patients with tuberculosis were lower in the intervention period than in the preintervention period (4 of 78 [5%] compared with 15 of 90 [17%] conversions; P = 0.02), decreasing to levels observed for workers assigned to other wards (4 of 78 [5%] compared with 9 of 228 [4%] conversions; P = 0.7).
  
  
  CONCLUSIONS
  Implementing control measures reduced nosocomial transmission of multidrug-resistant strains to patients and health care workers.
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA.
authors.forename: S A
authors.initials: SA
authors.lastname: Maloney
authors.forename: M L
authors.initials: ML
authors.lastname: Pearson
authors.forename: M T
authors.initials: MT
authors.lastname: Gordon
authors.forename: R
authors.initials: R
authors.lastname: Del Castillo
authors.forename: J F
authors.initials: JF
authors.lastname: Boyle
authors.forename: W R
authors.initials: WR
authors.lastname: Jarvis
mesh_terms: D000328:Adult; D003428:Cross Infection / Q000517:prevention & control* / Q000635:transmission*; D005260:Female; D006784:Hospitals, Teaching; D006801:Humans; D017053:Infection Control / Q000592:standards*; D017758:Infectious Disease Transmission, Patient-to-Professional; D017757:Infectious Disease Transmission, Professional-to-Patient; D008297:Male; D008875:Middle Aged; D009519:New York City; D010356:Patient Isolation; D010564:Personnel, Hospital; D012134:Respiratory Protective Devices; D012189:Retrospective Studies; D014374:Tuberculin Test; D018088:Tuberculosis, Multidrug-Resistant / Q000517:prevention & control* / Q000635:transmission*