Fluorescence microscopy for the diagnosis of smear-negative pulmonary tuberculosis in Ethiopia
African Journal of Laboratory Medicine
| Field | Value | |
| Title | Fluorescence microscopy for the diagnosis of smear-negative pulmonary tuberculosis in Ethiopia | |
| Creator | Abebe, Gemeda Aragaw, Dossegnaw Tadesse, Mulualem | |
| Description | Background: Despite its low sensitivity, microscopy remains the main method for the diagnosis of pulmonary tuberculosis in most laboratories in Ethiopia. Few studies have evaluated the performance of light-emitting diode fluorescent microscopy (LED-FM) in bleach-concentrated smear-negative sputum specimens.Objective: This study aimed to evaluate the diagnostic performance of LED-FM for smear-negative pulmonary tuberculosis in Ethiopia.Methods: A total of 194 adult patients with a cough lasting for more than two weeks, and who had three direct smear-negative sputum tests for Mycobacterium tuberculosis by Ziehl-Neelsen light microscopy, were included. All direct Ziehl-Neelsen-stained smear-negative sputum samples were cultured and were also visualised by LED-FM. Smears for LED-FM were performed from bleach-concentrated sputum sediment. The diagnostic performance of the LED-FM was compared to the culture method (the reference standard).Results: Of the 194 smear-negative sputum specimens analysed, 28 (14.4%) were culture-positive and 21 (10.8%) were LED-FM-positive for M. tuberculosis. However, only 11 of the 21 (52.4%) LED-FM-positive patients had a confirmed tuberculosis diagnosis by culture. Light-emitting diode fluorescence microscopy (FM) had a sensitivity of 39.3% (95% confidence interval: 21.2–57.4) and specificity of 93.9% (95% confidence interval: 90.4–97.6). Ten LED-FM-positive specimens were culture-negative, and all of these specimens had scanty grading (1–19 bacilli per 40 fields on LED-FM).Conclusion: This study showed that implementation of LED-FM on bleach pre-treated and concentrated sputum can significantly improve the diagnosis of smear-negative pulmonary tuberculosis. However, all scanty grade, positive smears by LED-FM need to be confirmed by reference culture method. | |
| Publisher | AOSIS | |
| Date | 2020-09-28 | |
| Identifier | 10.4102/ajlm.v9i1.810 | |
| Source | African Journal of Laboratory Medicine; Vol 9, No 1 (2020); 6 pages 2225-2010 2225-2002 | |
| Language | eng | |
| Relation |
The following web links (URLs) may trigger a file download or direct you to an alternative webpage to gain access to a publication file format of the published article:
https://ajlmonline.org/index.php/ajlm/article/view/810/1654
https://ajlmonline.org/index.php/ajlm/article/view/810/1653
https://ajlmonline.org/index.php/ajlm/article/view/810/1655
https://ajlmonline.org/index.php/ajlm/article/view/810/1652
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