title: Field assessment of the direct nitrate reductase assay for rapid detection of multidrug-resistant tuberculosis in Honduras.
abstract: METHODS
  The national TB reference laboratory and four health care units connected to the national laboratory network in Honduras, Central America.
  
  
  OBJECTIVE
  To evaluate the performance of the direct nitrate reductase assay (NRA) for rapid, low-cost detection of multidrug-resistant  tuberculosis (MDR-TB) in a resource-limited setting.
  
  
  METHODS
  Consecutive smear-positive samples (n = 185) were prospectively analysed with NRA and compared to the proportion method on Löwenstein Jensen medium (PM-LJ) to detect resistance to isoniazid (INH) and rifampicin  (RMP).
  
  
  RESULTS
  The NRA sensitivity, specificity, positive and negative predictive values for INH and RMP were respectively 100%, 99%, 91%, 100% and 80%, 100%, 100%, 99%. Good agreement was observed between NRA and PM-LJ (κ > 0.8).
  
  
  CONCLUSIONS
  The direct NRA is a reliable alternative  for rapid and low-cost identification of MDR-TB cases in resource-limited settings.
authors.affiliation: Escuela de Microbiología, Universidad Nacional Autónoma de Honduras, Tegucigalpa, Honduras. seniarosales@gmail.com
authors.forename: S
authors.initials: S
authors.lastname: Rosales
authors.forename: N
authors.initials: N
authors.lastname: Almendarez
authors.forename: H
authors.initials: H
authors.lastname: Membreño
authors.forename: S E
authors.initials: SE
authors.lastname: Hoffner
authors.forename: L
authors.initials: L
authors.lastname: Pineda-Garcia
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology*; D006721:Honduras; D006801:Humans; D007538:Isoniazid / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D050901:Nitrate Reductase / Q000378:metabolism*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012293:Rifampin / Q000494:pharmacology; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology; D018088:Tuberculosis, Multidrug-Resistant / Q000175:diagnosis* / Q000188:drug therapy / Q000201:enzymology
chemical_list: D000995:Antitubercular Agents; D050901:Nitrate Reductase; D007538:Isoniazid; D012293:Rifampin