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INTRODUCTION: Leprosy is a chronic infectious disease caused by Mycobacterium leprae (M. leprae). Histopathological examination of skin lesion is the gold standard for diagnosis. We evaluated the possible role of fluorescent microscopy in this direction which is increasingly used for rapid screening. AIM: To compare the efficacy of auramine rhodamine stain with Ziehl-Neelsen and modified Fite-faraco staining in diagnosing M. leprae in tissue sections. STUDY DESIGN: Experimental, cross-sectional and retrospective study conducted for 4 years. METHODS AND MATERIALS: Skin biopsies of sixty clinically diagnosed leprosy patients were stained by Ziehl-Neelsen, Fite-Faraco and fluorescent stain. The presence of the bacilli and the bacillary index was scored for each case. The bacillary index by each staining methods were compared. STATISTICAL ANALYSIS: SPSS v 17 (IBM, New York) used for data analysis. Chi-Square test was used to calculate significance between differences. The p-value of <0.05 was considered as statistically significant. Pearson Correlation (r-value determined) was also used for comparison between groups. RESULTS: Sensitivity of fluorescent stain for indeterminate and borderline tuberculoid leprosies were 100% each. Positivity rates and mean bacteriological index with fluorescent stain was higher (43.3 and 11.5 respectively) as compared to that of Ziehl- Neelsen and Fite-faraco when the bacillary load was less (bacillary index < 3). There was significant correlation between the three staining types at higher bacillary load. There was a higher mean bacillary index with fluorescent stain as well as detection of an additional multibacillary case. CONCLUSION: Fluorescent method is more sensitive than modified fite-faraco method in detecting lepra bacilli in tissue sections especially in cases with bacillary index less than three. With its higher sensitivity, paucibacillary cases could be upgraded to multibacillary thus affecting treatement decisions.
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BACKGROUND: Early detection of tuberculosis is important for reducing its morbidity and mortality especially in the patients with non-productive cough. To overcome the cumbersome process involved in collection and processing of the sputum specimen, the time consumed for reporting of sputum by Ziehl Neelsen (ZN) method and to introduce a routine screening test in suspected, symptomless tuberculosis patients, the present study was designed using saliva as diagnostic medium and Auramine Rhodamine (AR) as staining method. On review of literature, there was no study which has tried diagnosing tuberculosis using saliva with flurochrome stain; hence the present study was designed. AIM: To introduce a routine screening test for tuberculosis patient using saliva and to determine the diagnostic efficacy of routine ZN staining method and AR fluorescent staining method in sputum and saliva smears of pulmonary tuberculosis patients. SETTINGS AND DESIGN: Laboratory settings and Experimental design. MATERIALS AND METHOD: Fifty smears samples of sputum and saliva of known cases of pulmonary tuberculosis were stained with routine ZN stain and other with AR fluorescent stain. All the specimens were inoculated into Lowenstein-Jensen culture media. The smears were subjected for scanning of Mycobacterium tuberculous bacilli under X 1000 magnification for ZN stain and X 400 magnification for AR stain by grid pattern proposed by National tuberculosis institute and graded by RNTCP grading system. RESULTS: All 50 sputum samples showed 100% positivity by ZN and AR stain while only 76% positivity was seen by culture. Of the 50 saliva samples 10% cases were positive by ZN, 76% were positive by AR & 70% by culture method. Statistical analysis using chi square test was done, and the value was found to be statistically highly significant for AR staining technique. (p<0.001) CONCLUSION: Saliva can prove to be an important tool for the diagnosis as well as screening of the patients with pulmonary tuberculosis when aided with flurochrome staining method.