title: Manual MGIT™ system for the detection of Mycobacterium tuberculosis: insights from a high TB burden setting.
abstract: OBJECTIVE
  To evaluate the diagnostic performance of manual MGIT™ (MMGIT) compared to the gold standard, Löwenstein-Jensen (LJ), in the diagnosis of pulmonary tuberculosis (TB) in a high-burden setting.
  
  
  METHODS
  Individuals with suspected TB enrolled in parallel diagnostic trials during 2007-2011 were included. Two samples were obtained from each patient and inoculated into MMGIT and LJ medium. Diagnostic tests were performed, and the incremental yield of a second test and time to detection (TTD) were calculated. Analyses were performed per patient and per sample. Gold standard was based on LJ culture.
  
  
  RESULTS
  In the per patient and per sample analysis, we evaluated 1436 patients and 4142 samples. The sensitivity and specificity for smear and MMGIT per sample were respectively 89.9%/92.2% and 97.1%/98.9%. Contamination was observed in 1.4% of samples on MMGIT. The mean TTD (days) was 11.8 for MMGIT and 22.9 for LJ. The sensitivity and specificity for smear and MMGIT per patient were respectively 89.9% and 92.2% and 97.1% and 98.3%. A second MMGIT culture had an incremental yield of 1.6%.
  
  
  CONCLUSIONS
  MMGIT has high sensitivity and specificity, regardless of smear result, with a 50% reduction in TTD compared to LJ. These features make MMGIT an acceptable TB diagnostic method for use in resource-limited settings.
authors.affiliation: Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru.
authors.forename: R
authors.initials: R
authors.lastname: Quispe
authors.affiliation: Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru.
authors.forename: G A
authors.initials: GA
authors.lastname: Valle
authors.affiliation: School of Medicine, Universidad Peruana Cayetano Heredia, Lima, Peru.
authors.forename: J A
authors.initials: JA
authors.lastname: Huapaya
authors.affiliation: Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru.
authors.forename: I
authors.initials: I
authors.lastname: Novoa
authors.affiliation: Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru.
authors.forename: J
authors.initials: J
authors.lastname: Giraldo
authors.affiliation: Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru.
authors.forename: T
authors.initials: T
authors.lastname: Caceres
authors.affiliation: Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru; Departamento de Enfermedades Infecciosas, Tropicales y Dermatológicas, Hospital Nacional Cayetano Heredia, Lima, Peru.
authors.forename: E
authors.initials: E
authors.lastname: Gotuzzo
authors.affiliation: Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru.
authors.forename: C
authors.initials: C
authors.lastname: Zamudio
authors.affiliation: Instituto de Medicina Tropical Alexander von Humboldt, Departamento de Enfermedades Infecciosas, Tropicales y Dermatológicas, Hospital Nacional Cayetano Heredia, Lima, Peru.
authors.forename: C
authors.initials: C
authors.lastname: Seas
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001431:Bacteriological Techniques / Q000191:economics; D005260:Female; D017048:Health Care Costs; D006801:Humans; D008168:Lung / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D010568:Peru / Q000453:epidemiology; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013183:Sputum / Q000382:microbiology; D013997:Time Factors; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000191:economics / Q000453:epidemiology / Q000382:microbiology; D055815:Young Adult