Front-loaded smear microscopy for the diagnosis of pulmonary TB in Tripoli, Libya



Gammo M, Lamaric W, Hadida M, Abuazza A, Askar NA, Yassin MA, Cuevas LE.


Trans R Soc Trop Med Hyg. 2013 Feb;107(2):137-9. doi: 10.1093/trstmh/trs023. Epub 2012 Dec 14.


BACKGROUND: Diagnosis of pulmonary TB by conventional smear microscopy requires patient attendance on 2 consecutive days. We investigated whether collecting sputum on-the-spot for smear microscopy on the day the patient presented was as sensitive and specific for diagnosis as the conventional spot-morning-spot scheme. METHOD: We enrolled 412 adults who presented between January 2009 and October 2010 at the National Centre for TB Control in Tripoli, Libya, with cough of >2 weeks’ duration, into a cross-sectional survey collecting four sputum specimens: on-the-spot and Xspot on Day 1; morning and on-the-spot on Day 2. RESULTS: 97 (24%) of 401 culture results were culture positive. Spot-Xspot and spot-morning smear microscopy had, respectively, 65% and 66% sensitivity and 97% and 96% specificity (p > 0.5). Spot-Xspot-morning and Spot-morning-spot smear-microscopy had, respectively, 67% and 66% sensitivity and 96% and 96% specificity (p > 0.5). CONCLUSION: For the diagnosis of pulmonary TB, the sensitivity and specificity of front-loaded (same-day) smear microscopy is similar to that of the standard smear microscopy scheme.

Keywords: .

Link/DOI: 10.1093/trstmh/trs023