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.
