PLoS ONE (Jan 2021)

Diagnostic efficacy of Light-Emitting Diode (LED) Fluorescence based Microscope for the diagnosis of Tuberculous lymphadenitis.

  • Gebeyehu Assefa,
  • Kassu Desta,
  • Shambel Araya,
  • Selfu Girma,
  • Adane Mihret,
  • Tsegaye Hailu,
  • Abay Atnafu,
  • Nigatu Endalafer,
  • Adugna Abera,
  • Shiferaw Bekele,
  • Leila Birhanu,
  • Getu Diriba,
  • Yordanos Mengistu,
  • Biniyam Dagne,
  • Kidist Bobosha,
  • Abraham Aseffa

DOI
https://doi.org/10.1371/journal.pone.0255146
Journal volume & issue
Vol. 16, no. 7
p. e0255146

Abstract

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BackgroundThe comparatively straightforward and cheaper light-emitting diode fluorescent microscope (LEDFM) was suggested by WHO to replace conventional microscope in tuberculosis (TB) laboratories. However, the comparable efficacy of each of those techniques differs from laboratory to laboratory. We investigated the efficacy of LEDFM for the diagnosis of tuberculous lymphadenitis (TBLN) patients.MethodsA cross-sectional study was conducted on 211 samples from clinically suspected tuberculous lymphadenitis patients. Three smears were prepared from FNA on microscope slides for cytomorphology study, Auramine O (AO), and for Ziehl-Neelsen (ZN) staining. The left-over samples were inoculated onto Lowenstein-Jensen (LJ) media. Statistical analysis was done using STATA version 11. The sensitivity, specificity, positive and negative predictive values were calculated by considering the culture results as the gold standard using a 95% confidence interval.ResultsAmong 211 samples 49.7% (105) were positive by cytomorphology, 32.7% (69) by LEDFM, 23.69% (50) by LJ culture, and 13.7% (29) by ZN. Compared to the gold standard sensitivity of ZN, LEDFM, and cytomorphology were 30% [95% CI: 17.9-44.6], 66% [95% CI: 51.2-78.8] 78% [95% CI: 64-88.5], respectively. The specificity of ZN, LEDFM, and cytomorphology was 91.3% [95% CI: 85.8-95.2], 77.6% [95% CI: 70.4-83.8], 58.8% [95% CI: 50.7-66.5], respectively.ConclusionLED fluorescence microscopy gives a legitimate option in contrast to conventional ZN techniques in terms of its higher sensitivity, a bit lower specificity, time-saving, and minimal effort.