COMPARATIVE ASSESSMENT OF DIFFERENT DIAGNOSTIC TECHNIQUES IN THE IDENTIFICATION OF MYCOBACTERIUM TUBERCULOSIS IN SUSPECTED CASES OF TUBERCULOSIS

Abstract

Statement of the Problem: Tuberculosis remains a serious public-health threat in developing countries though it has been eradicated in some advanced countries. This disease constitutes a significant threat to global health, being the second highest cause of morbidity and mortality resulting from infectious agents. Prompt diagnosis of active TB facilitates timely therapeutic intervention and minimizes community transmission. Aim: This study aimed at determining a ‘Point of Care’ diagnostic tool for pulmonary tuberculosis (PTB) by comparing the efficiency of four different PTB diagnostic tools for different age groups. Methodology: Zeihl Nelson (ZN) staining, culture, Gene xpert (GX) and Lipoarabinomanan (LAM) assay were employed in this study The culture method was used for confirmation. Sputum and urine samples were collected from each of 100 patients symptomatically diagnosed of PTB. Findings: Fifty-seven percent of the population was male while 43% were female. Mycobacterium tuberculosis was isolated from 9 (9%) of 100 patients. Similarly, GX detected Mycobacterium tuberculosis in 9 (9%) of the patients while the rate of detection using LAM was 10% and with ZN it was 7%. Gene xpert produced no true or false positive and negative result, LAM had one false positive result and ZN had two false negative results. The maximum time frame to generate result was 25 minutes for LAM, two hours for Gene xpert, eight weeks for culture and two days for ZN. Two positive isolates were observed at the same frequency for age group 21-30 and 31- 40 while age groups 1-10, 10-20, 41-50, 50-60 and above has 1 positive result each. Gene xpert had 98.11% sensitivity while LAM had 96.23% and ZN had 86.79%. The choice of ‘Point of Care’ diagnostic tool is of great concern to clinicians and the general public. Conclusion & Significance: This study identified LAM assay as suitable ‘Point of Care’ diagnostic and an add-on tool for PTB diagnosis because of its relatively high sensitivity and short maximum time frame to generate result compare to other three diagnostic techniques.