A Thesis submitted to the collage of Health science of Jimma university , department of epidemiology in partiality fulfillment of the requirement for degree of master of public health

Abstract

Back ground:-Conventional light microscopy using Ziehl-Neelsen stained smears from sputum specimens is widely available test for diagnosis of tuberculosis in resource-limited settings. However, a major shortcoming is its low sensitivity compared with culture. Objective:-To compared efficacy of Direct LED fluorescence microscopy with concentrated Ziehl-Neelsen microscopy techniques against Mycobacterial culture of sputum sample Method:- The study design were a cross-sectional , in the outpatient departments of St. Merry Aksum hospital, from September, 2015 to December, 2015 was conducted Three consecutive sputum specimens from patients who fulfilled entry criteria were processed. Direct smear were stained using auramine phenol and Concentrated slides using bleach were stained by Ziehl Neelsen techniques method with culture as the gold standard. Three hundrades and ninety four sputa were processed. The data were summarized and organized in tables and described with different descriptive measures. Associations were analyzed usingX2 – test and the kappa-test. Result:-The sensitivity, specificity, positive and negative predictive values achieved with direct LED FM compared to culture were 71.59%, 98.03%, 91.3% and 92.3% respectively. Inter-test agreement between Direct LED FM and LJ culture systems determined by using the kappa-test were (Kappa (κ) = 0.754), and the observed agreement was found to be also statistically significant (p = 0.042).A comparison of concentrated ZN and direct FM smear results showed that, direct LED FM sensitivity was significantly higher than concentrated ZN microscopy (63.63% vs 71.59%,P<0.001) but FM specificity was slightly lower(98.3% vs 100%). Conclusion and Recommendation:- our results strongly suggest that the optimum detection of AFB is achieved by the auramine-O fluorescent staining using Light Emitting Diode Fluorescent Microscopy the concentrated Ziehl-Neelsen And .Federal Ministry of Health and Tigray region health bureau in collaboration with other stakeholders should encourage further implementation LED based fluorescent microscopy. They should strengthen and support pulmonary tuberculosis prevention and control programs.