title: Reliability of the MODS assay decentralisation process in three health regions in Peru.
abstract: OBJECTIVE
  To deliver rapid isoniazid (INH) and rifampicin (RMP) drug susceptibility testing (DST) close to the patient, we designed a decentralisation process for the microscopic observation drug susceptibility (MODS) assay in Peru and evaluated its reliability.
  
  
  METHODS
  After 2 weeks of training, laboratory staff processed ≥ 120 consecutive sputum samples each in three regional laboratories. Samples were processed in parallel with MODS testing at an expert laboratory. Blinded paired results were independently analysed by the Instituto Nacional de Salud (INS) according to pre-determined criteria: concordance for culture, DST against INH and RMP and diagnosis of multidrug-resistant tuberculosis (MDR-TB) ≥ 95%, McNemar's P > 0.05, kappa index (κ) ≥ 0.75 and contamination 1-4%. Sensitivity and specificity for MDR-TB were calculated.
  
  
  RESULTS
  The accreditation process for Callao (126 samples, 79.4% smear-positive), Lima Sur (n = 130, 84%) and Arequipa (n = 126, 80%) took respectively 94, 97 and 173 days. Pre-determined criteria in all regional laboratories were above expected values. The sensitivity and specificity for detecting MDR-TB in regional laboratories were >95%, except for sensitivity in Lima Sur, which was 91.7%. Contamination was 1.0-2.3%. Mean delay to positive MODS results was 9.9-12.9 days.
  
  
  CONCLUSIONS
  Technology transfer of MODS was reliable, effective and fast, enabling the INS to accredit regional laboratories swiftly.
authors.affiliation: Centro Nacional de Salud Pública, Instituto Nacional de Salud de Perú, Lima, Peru. mendozalberto@hotmail.com
authors.forename: A
authors.initials: A
authors.lastname: Mendoza
authors.forename: E
authors.initials: E
authors.lastname: Castillo
authors.forename: N
authors.initials: N
authors.lastname: Gamarra
authors.forename: T
authors.initials: T
authors.lastname: Huamán
authors.forename: M
authors.initials: M
authors.lastname: Perea
authors.forename: Y
authors.initials: Y
authors.lastname: Monroi
authors.forename: R
authors.initials: R
authors.lastname: Salazar
authors.forename: J
authors.initials: J
authors.lastname: Coronel
authors.forename: M
authors.initials: M
authors.lastname: Acurio
authors.forename: G
authors.initials: G
authors.lastname: Obregón
authors.forename: M
authors.initials: M
authors.lastname: Roper
authors.forename: C
authors.initials: C
authors.lastname: Bonilla
authors.forename: L
authors.initials: L
authors.lastname: Asencios
authors.forename: D A J
authors.initials: DA
authors.lastname: Moore
mesh_terms: D000068:Accreditation; D000995:Antitubercular Agents; D019411:Clinical Laboratory Techniques / Q000592:standards; D006801:Humans; D007538:Isoniazid; D008826:Microbial Sensitivity Tests / Q000592:standards; D008853:Microscopy; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D015588:Observer Variation; D010568:Peru; D011237:Predictive Value of Tests; D012040:Regional Health Planning; D015203:Reproducibility of Results; D012293:Rifampin; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology*; D018088:Tuberculosis, Multidrug-Resistant / Q000175:diagnosis* / Q000382:microbiology
chemical_list: D000995:Antitubercular Agents; D007538:Isoniazid; D012293:Rifampin