title: Quality control in the laboratory diagnosis of tuberculosis.
abstract: The study was conducted in 4 hospital laboratories to assess the value of smear re-examination, duplicate smear and culture in quality control in the diagnosis of pulmonary tuberculosis. In each hospital 1 to 3 sputum specimens were collected from each suspect and examined by the Ziehl-Neelsen method. Smears along with corresponding specimens were sent to the reference laboratory for re-examination and examination of fresh duplicate smears and culture. A total of 994 specimens plus 23 known negative and 23 known positive controls were analysed. For each assessment method, both over-diagnosis and underdiagnosis were indicated with under-diagnosis being a more common problem in the four hospital laboratories. The limitations of these assessment methods are presented.
authors.affiliation: Kenya Medical Research Institute, Biomedical Sciences Research Centre.
authors.forename: M G
authors.initials: MG
authors.lastname: Kinyanjui
authors.forename: W A
authors.initials: WA
authors.lastname: Githui
authors.forename: R G
authors.initials: RG
authors.lastname: Kamunyi
authors.forename: M J
authors.initials: MJ
authors.lastname: Omwega
authors.forename: P G
authors.initials: PG
authors.lastname: Waiyaki
authors.forename: L N
authors.initials: LN
authors.lastname: Muthami
mesh_terms: D005069:Evaluation Studies as Topic; D006801:Humans; D007630:Kenya / Q000453:epidemiology; D007755:Laboratories, Hospital / Q000592:standards*; D011786:Quality Control; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology