title: Does DOTS work in populations with drug-resistant tuberculosis?
abstract: BACKGROUND
  Directly observed therapy (DOTS) is the main strategy for prevention and control of tuberculosis worldwide. However, its effect on tuberculosis transmission in populations with moderate rates of drug-resistant disease is not known.
  
  
  METHODS
  This population-based prospective study in southern Mexico between March, 1995, and February, 2000, was based on passive case finding and detection of acid-fast bacilli in sputum samples to diagnose pulmonary tuberculosis. We also used cultures, drug-susceptibility testing, bacterial genotyping, and monitoring of treatment outcomes.
  
  
  RESULTS
  We enrolled 436 patients; the HIV seroprevalence rate was 2%. We used three indicators to monitor continuing tuberculosis transmission: the incidence rate of pulmonary tuberculosis, which decreased by 54.4% between 1995 and 2000, from 42.1 to 19.2 per 10(5) population (p=0.00048); the percentage of clustered pulmonary tuberculosis cases, which decreased by 62.6% from 22% to 8% (p=0.02); and the rate of primary drug resistance, which decreased by 84.0% from 9.4 to 1.5 per 10(5) population (p=0.004). Rates of multidrug-resistant (MDR) tuberculosis also decreased (p<0.0001). The case-fatality ratio was 12% for MDR tuberculosis (five of 41), 7% for strains resistant to at least one drug after exclusion of MDR (four of 55), and 3% for pansusceptible strains (nine of 272). There were 13 treatment failures (11%) in 1995 and one (2%) in 2000 (p=0.012).
  
  
  CONCLUSIONS
  Even in settings with moderate rates of MDR tuberculosis, DOTS can rapidly reduce the transmission and incidence of both drug-susceptible and drug-resistant tuberculosis. However, further interventions, such as drug-susceptibility testing and standardised or individualised treatment regimens, are needed to reduce mortality rates for MDR tuberculosis.
authors.affiliation: Division of Infectious Diseases and Geographic Medicine, Stanford University Medical Center, Stanford, CA, USA.
authors.forename: Kathryn
authors.initials: K
authors.lastname: DeRiemer
authors.forename: Lourdes
authors.initials: L
authors.lastname: García-García
authors.forename: Miriam
authors.initials: M
authors.lastname: Bobadilla-del-Valle
authors.forename: Manuel
authors.initials: M
authors.lastname: Palacios-Martínez
authors.forename: Areli
authors.initials: A
authors.lastname: Martínez-Gamboa
authors.forename: Peter M
authors.initials: PM
authors.lastname: Small
authors.forename: José
authors.initials: J
authors.lastname: Sifuentes-Osornio
authors.forename: Alfredo
authors.initials: A
authors.lastname: Ponce-de-León
mesh_terms: D023801:Directly Observed Therapy; D006801:Humans; D015994:Incidence; D008800:Mexico / Q000453:epidemiology; D018088:Tuberculosis, Multidrug-Resistant / Q000188:drug therapy* / Q000453:epidemiology / Q000517:prevention & control; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy* / Q000453:epidemiology / Q000517:prevention & control