title: Evolution in the resistance of Mycobacterium tuberculosis to anti-tuberculosis drugs in Nicaragua.
abstract: METHODS
  Nicaragua, a country where the DOTS strategy has been successfully implemented since 1984.
  
  
  OBJECTIVE
  To estimate the prevalence and trends of Mycobacterium tuberculosis resistance to first-line anti-tuberculosis drugs.
  
  
  METHODS
  A prospective national survey carried out in 2004 according to the standardised model developed by the World Health Organisation and the International Union Against Tuberculosis and Lung Disease.
  
  
  RESULTS
  A total of 423 M. tuberculosis strains were studied. Among the 320 strains evaluated for initial resistance, 13.1% displayed resistance to any drug, lower than the 1998 figure of 15.6%. Overall initial resistance to isoniazid (INH), rifampicin (RMP) and multidrug resistance (MDR) was respectively 6.6%, 0.9% and 0.6%. Initial resistance was higher in older age groups. Overall acquired resistance was 35.9% (n = 103); resistance to INH was 29.3% and to RMP 8.9%, while MDR was 7.9%. The acquired MDR rate was clearly higher in Category I failures (44.4%) than in relapses (3.8%) and retrieved defaulters (2.7%). All resistance rates found in this study were lower than those detected in 1998.
  
  
  CONCLUSIONS
  This study shows low rates of resistance and MDR and a downward trend in all rates, undoubtedly related to the proper implementation of the National Tuberculosis Programme.
authors.affiliation: Departamento de Micobacterias, Centro Nacional de Diagnóstico y Referencia (CNDR), Ministerio de Salud (MINSA), Managua, Nicaragua.
authors.forename: L
authors.initials: L
authors.lastname: Chacón
authors.forename: M
authors.initials: M
authors.lastname: Lainez
authors.forename: E
authors.initials: E
authors.lastname: Rosales
authors.forename: M
authors.initials: M
authors.lastname: Mercado
authors.forename: J A
authors.initials: JA
authors.lastname: Caminero
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D006306:Health Surveys; D006801:Humans; D007538:Isoniazid / Q000494:pharmacology; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D009527:Nicaragua / Q000453:epidemiology; D015995:Prevalence; D013307:Streptomycin / Q000494:pharmacology; D018088:Tuberculosis, Multidrug-Resistant / Q000453:epidemiology* / Q000517:prevention & control; D014397:Tuberculosis, Pulmonary / Q000453:epidemiology* / Q000517:prevention & control
chemical_list: D000995:Antitubercular Agents; D007538:Isoniazid; D013307:Streptomycin