Fluorescence Microscopy: A useful diagnostic tool for Pulmonary Tuberculosis. (Study of 23,506 cases)

Abstract

Abstract.

Background:  Pulmonary Tuberculosis is a significant cause of preventable mortality and is an important public health issue over the world.  About 33% of the globe population is infected with Mycobacterium Tuberculosis and Pakistan is among high burden countries. Rapid Mycobacterial detection and prompt treatment is a matter of concern for an effective tuberculosis control program.  Use of sputum smear microscopy by Ziehl-Neelsen stain method is the routine practice in resource limited populations but it displays significant false-negative rate. Fluorescent Microscopy is quick, easy and can enhance the diagnostic yield.

Objective: To determine the sensitivity, specificity and diagnostic accuracy of fluorescence microscopy for Pulmonary Tuberculosis.

Materials and Method: This cross-sectional study was conducted at OPD-Gulab Devi Chest Hospital Lahore from 1^st January 2019 to 31^st December, 2019. Consecutive 23,506 adult patients with clinical features and radiographic signs consistent with pulmonary tuberculosis were included while those without any suspicion of tuberculosis were excluded. After history and thorough physical examination, two sputa of the patient were examined by Fluorescent Microscopy. Patients were also subjected to CBC with ESR.  Anti-TB treatment was initiated and completed according to DOTS strategy. The response to treatment was considered as reference. All findings were noted, tabulated. SPSS-21 soft-ware was used for statistical analysis.

Results: Of 23,506 patients, 5,419 sputa were positive for AFB with sensitivity 72.95%, specificity 99.93%, PPV 99.80%, NPV 88.91% and diagnostic accuracy 91.42%.

Conclusions:  Fluorescence Microscopy is an efficacious modality for diagnosing pulmonary tuberculosis.

 Key Words: Sputum smear-Fluorescent stain-Microscopy-Pulmonary-TB-Diagnosis-Accuracy.