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Journal of Preventive Medicine and Holistic Health


Light Emitting Diode(LED) Fluorescence Microscopy(FM) for Same Day Diagnosis of Pulmonary Tuberculosis(PBT)


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Author Details: Paramjyothi G.K, Rajesh Kumar Jain S.

Volume : 1

Issue : 2

Online ISSN : 2454-6712

Print ISSN : 2454-6704

Article First Page : 73

Article End Page : 83


Abstract

Background: The conventional approach for the diagnosis of pulmonary tuberculosis (PTB) involves collection of sputum sample for several days for which the patient makes multiple visits to health care center and does not take patients inconvenience into account. The sputum smears are stained by Ziehl-Neelsen (ZN) method and examined under light microscopy (LM) which is relatively insensitive diagnostic technique.
Aims and Objectives:

1) Evaluate the role of LM-ZN and light emitting diode (LED) fluorescent microscopy (FM) on spot samples collected 1 hour apart on first day and early morning sample collected on second day, in diagnosis of PTB.
2) Determine whether spot-specimen LED-FM is not inferior to conventional two specimens LED-FM.
3) Evaluate the diagnostic yield of overnight sputum with LM-ZN and LED-FM.
4) Compare the diagnostic yield between LED-FM and LM-ZN. 5) Determine the “loss to follow-up during diagnostic period”.
Methods: All the presumptive PTB cases attending Department of Pulmonary Medicine, Navodaya Medical College Hospital and Research Institute, Raichur, including both in-patients and out-patients from 1st October 2011 to 30th April 2012 after informed consent were enrolled for the study. Total 3 sputum samples were collected from each patient (two spot sputum samples one hour apart and next day early morning sputum sample). Patients who failed to submit less than 3 sputum sample, were labelled as “lost to follow-up during diagnostic period”. Four slides are prepared from each sputum specimen of which two slides from each sputum specimen are examined by LM following ZN staining and the remaining two slides are examined by FM following Auramine-O (AO) staining as per Revised National Tuberculosis Control Programme (RNTCP) guidelines.
Results: A total of 552 patients participated in our study, 492 patients (89.13%) submitted all the 3 sputum samples, whereas 60 patients (10.86%) were lost to follow-up during diagnostic period. Totally 80 cases (14.49%) were diagnosed as sputum smear positive (SSP) PTB. Among 492 cases who submitted all the 3 sputum samples, 67 cases (12.13%) were diagnosed as SSP-PTB and among the 60 cases lost to follow-up during diagnostic period, 13 (2.35%) cases were diagnosed as SSP-PTB. The 95% confidence interval (CI) for 1 hour apart sample is 9.88%-30.12% whereas the CI for the early morning sample is 94.45%-100%.
Conclusions: AO LED-FM is superior to ZN-LM in detection of SSP-PTB. Two smears prepared from a single sputum specimen had no potential role to improve the diagnostic efficiency of PTB among presumptive PTB cases. The loss to follow-up during diagnostic period in our study was 10.86%. Even though the yield is best with early morning sample, in view of high loss to follow-up during diagnostic period for early morning sputum sample, two spot sputum samples collected one hour apart and using AO-FM can be considered for diagnosis of PTB in presumptive cases for better global TB control.

Key Words: Tuberculosis, ZN Staining, Fluores Staining.