Use of light-emitting diode fluorescence microscopy to detect acid-fast bacilli in sputum as proficient alternative tool in the diagnosis of pulmonary tuberculosis in countries with limited resource settings

• DOI: 10.4103/ijmy.ijmy_13_23
• Publication Date: 2023-06-16T13:31:22Z
• Authors: AntièméCombo Geor...; Gagni Coulibaly; AnouMoise Somboro; Mahamadou Kone; FahGaoussou Traore; Fatimata Diallo; Boureima Degoga; Amadou Somboro; HawaM'baye Dramé; Moumine Sanogo; Ousmane Kodio; Bocar Baya; Mohamed Tolofoudie; Aminata Maiga; Mamoudou Maiga; Katy Saliba-Shaw; Souleymane Diallo; Seydou Doumbia; IbrahimIzetiégoum...; Fassé Samaké; Bassirou Diarra
• Keywords: Rhodamines; Sputum; light emitting diode fluorescence microscopy; Mycobacterium tuberculosis; Microbiology; Sensitivity and Specificity; QR1-502; 3. Good health; fluorescein di-acetate; tuberculosis; Microscopy, Fluorescence; Benzophenoneidum; Humans; Tuberculosis; Fluorescein; Tuberculosis, Pulmonary

Despite recent advances in the development of more sensitive technologies for the diagnosis of tuberculosis (TB), in resource-limited settings, the diagnosis continues to rely on sputum smear microscopy. This is because smear microscopy is simple, cost-efficient and the most accessible tool for the diagnosis of TB. Our study evaluated the performance of light-emitting diode fluorescence microscopy (LED-FM) using auramine/rhodamine (auramine) and the fluorescein di-acetate (FDA) vital stain in the diagnostic of pulmonary TB in Bamako, Mali.Sputum smear microscopy was conducted using the FDA and auramine/rhodamine staining procedures on fresh samples using LED-FM to evaluate the Mycobacterium TB (MTB) metabolic activity and to predict contagiousness. Mycobacterial culture assay was utilized as a gold standard method.Out of 1401 TB suspected patients, 1354 (96.65%) were retrieved from database, which were MTB complex culture positive, and 47 (3.40%) were culture negative (no mycobacterial growth observed). Out of the 1354 included patients, 1343 (95.86%), were acid-fast bacillus (AFB) positive after direct FDA staining, 1352 (96.50%) AFB positive after direct Auramine, and 1354 (96.65%) AFB positive with indirect auramine after digestion and centrifugation. Overall, the FDA staining method has a sensitivity of 98.82%, while the sensitivity of Auramine with direct observation was 99.48%, and 99.56% with the indirect examination.This study showed that, using fresh sputum both auramine/rhodamine and FDA are highly sensitive methods in diagnosing pulmonary TB and could be easily used in countries with limited resource settings.