A Comparative Study of Auramine O Staining Using LED Fluorescent Microscopy with Ziehl –Neelsen Staining in the Examination of Sputum For Acid Fast Bacilli

Background: Despite all interventions, tuberculosis (TB) remains a public health issue in Nigeria.Effective TB treatment and control demand early case detection.The ZN staining technique, which is the method of choice in the DOTS program can have problem of low sensitivity.Hence, the need for more sensitive alternative methods.Use of culture is the gold standard but it is not feasible in resource limited settings.The fluorescent Light Emitting Diode (LED) microscopy (FM) method using auramine O stain offers a viable alternative.Aims and Objectives: To study the efficacy of the fluorescent LED microscopy in the diagnosis of pulmonary tuberculosis (PTB) in comparison with the Z N method and to determine which of the methods is faster in the detection of Acid Fast Bacilli (AFB).Methodology: Early morning sputum samples were collected from 630 pulmonary tuberculosis suspects (PTB) attending the TB (DOTS) centre of Nnamdi Azikiwe University Teaching Hospital, Nnewi, Nigeria.Two smears, measuring 1x2 cm in diameter, made from each specimen received were stained, one with Ziehl Neelsen staining method and the other with auramine O fluorescent staining method.Results: Microscopy results obtained from both methods were recorded according to the IUALTD/WHO guideline as adopted by the National Tuberculosis programme (NTP).The results showed comparable sensitivities.The positivity rate was 51/630(8.1%)for ZN and 55/630(8.7%)for FM.However, FM was found to be faster than ZN technique.Conclusions: The faster reading and the ease of use of the LED fluorescent microscope together with its general acceptability actually support its use in the DOTS program, not as an alternative but as an adjuvant, especially during the introductory phase which should be monitored.