title: Laboratory implementation of the polymerase chain reaction for confirmation of pulmonary tuberculosis.
abstract: Decision analysis methods were used to compare four mycobacteriology laboratory strategies with respect to time to confirmation and exclusion of smear-positive and smear-negative cases of pulmonary tuberculosis. Strategies assessed included the following: (i) polymerase chain reaction (PCR) on all respiratory specimens; (ii) PCR on smear-positive specimens and on the broth of vials for other specimens attaining a growth index >10 in a radiometric culture detection system; (iii) PCR on smear-positive specimens only; and (iv) radiometric culture detection, with DNA probe for species identification of vials attaining a growth index >999. Strategies i and ii had predicted average times to confirm cases of 5 and 7.6 days, respectively, and remained within 3 days of each other over a broad range of PCR performance with smear-negative specimens. In contrast, case-confirmation times using strategies iii and iv were 10.4 and 15.3 days, respectively. Only 10% of specimens were processed by PCR in strategy ii. Times to confirm smear-negative cases were comparable for strategies i and ii when PCR sensitivity was <40% with these specimens. Times to exclude pulmonary tuberculosis were similar for all strategies. Given the current suboptimal performance of PCR with smear-negative specimens, strategy ii offers accelerated case confirmation with limited PCR usage.
authors: McGill University, Montreal, Quebec, Canada.
authors: N V
authors: NV
authors: Rau
authors: M D
authors: MD
authors: Libman
mesh_terms: D001431:Bacteriological Techniques; D019411:Clinical Laboratory Techniques; D004269:DNA, Bacterial / Q000032:analysis; D003661:Decision Support Techniques; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*
chemical_list: D004269:DNA, Bacterial