Performance of LED-Based Fluorescence Microscopy to Diagnose Tuberculosis in a Peripheral Health Centre in Nairobi
Open Access
- 18 February 2011
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 6 (2), e17214
- https://doi.org/10.1371/journal.pone.0017214
Abstract
Sputum microscopy is the only tuberculosis (TB) diagnostic available at peripheral levels of care in resource limited countries. Its sensitivity is low, particularly in high HIV prevalence settings. Fluorescence microscopy (FM) can improve performance of microscopy and with the new light emitting diode (LED) technologies could be appropriate for peripheral settings. The study aimed to compare the performance of LED-FM versus Ziehl-Neelsen (ZN) microscopy and to assess feasibility of LED-FM at a low level of care in a high HIV prevalence country. A prospective study was conducted in an urban health clinic in Nairobi, Kenya. Three sputum specimens were collected over 2 days from suspected TB patients. Each sample was processed with Auramine O and ZN methods and a 4th specimen was collected for TB culture reference standard. Auramine smears were read using the same microscope, equipped with the FluoLED™ fluorescence illuminator. Inter-reader agreement, reading time and technicians' acceptability assessed feasibility. 497 patients were included and 1394 specimens were collected. The detection yields of LED-FM and ZN microscopy were 20.3% and 20.6% (p = 0.64), respectively. Sensitivity was 73.2% for LED-FM and 72% for ZN microscopy, p = 0.32. It was 96.7% and 95.9% for specificity, p = 0.53. Inter-reader agreement was high (kappa = 0.9). Mean reading time was three times faster than ZN microscopy with very good acceptance by technicians. Although it did not increase sensitivity, the faster reading time combined with very good acceptance and ease of use supports the introduction of LED-FM at the peripheral laboratory level of high TB and HIV burden countries.Keywords
This publication has 24 references indexed in Scilit:
- Integrated Strategies to Optimize Sputum Smear MicroscopyAmerican Journal of Respiratory and Critical Care Medicine, 2011
- New and improved tuberculosis diagnostics: evidence, policy, practice, and impactCurrent Opinion in Pulmonary Medicine, 2010
- Comparison of two LED fluorescence microscopy build-on modules for acid-fast smear microscopy.2010
- Light-emitting diode technologies for TB diagnosis: what is on the market?Expert Review of Medical Devices, 2009
- Bleach Sedimentation: An Opportunity to Optimize Smear Microscopy for Tuberculosis Diagnosis in Settings of High Prevalence of HIVClinical Infectious Diseases, 2008
- Reducing the number of sputum samples examined and thresholds for positivity: an opportunity to optimise smear microscopy.2007
- Yield of serial sputum specimen examinations in the diagnosis of pulmonary tuberculosis: a systematic review.2007
- Light emitting diodes for auramine O fluorescence microscopic screening of Mycobacterium tuberculosis.2006
- Scanty AFB smears: what's in a name?2004
- The impact of human immunodeficiency virus on presentation and diagnosis of tuberculosis in a cohort study in Zambia.1993