Open AccessDETECTION FAILURE OF SMEAR MICROSCOPY TO CONFIRM PULMONARY TUBERCULOSIS
Author(s) -
Yunusa EU,
Bakare AT,
Shagari GB,
Abubakar AM,
Y Sharhabila,
A Yunusa,
Ango UM,
Umar MT
Publication year - 2018
Publication title -
caliphate medical journal
Language(s) - English
Resource type - Journals
eISSN - 2346-7207
pISSN - 2346-7193
DOI - 10.47837/cmj.19770126.20186141124
Subject(s) - tuberculosis , medicine , pulmonary tuberculosis , gold standard (test) , mycobacterium tuberculosis , polymerase chain reaction , pathology , biology , biochemistry , gene
Background: The laboratories in poor resource settings commonly use smear microscopy for the diagnosis of pulmonary tuberculosis, because it is rapid, inexpensive and easy to perform. The commonly use Lowensten Jensen culture method for the diagnosis of tuberculosis is slow and usually not very sensitive. Polymerase Chain Reaction (PCR) in the diagnosis of tuberculosis (TB) has come to stay as an effective diagnostic tool for effective pulmonary TB case detections. Objectives: This is to promote and encourage utilization of molecular diagnostic method (PCR) for the diagnosis of tuberculosis especially in smear negative microscopy suspected cases to reduce the rate of missed diagnosis. Material and Methods: This was an observational cross sectional prospective study among patients who presented at tuberculosis reference laboratory with request form for the diagnosis of pulmonary tuberculosis. Consent forms were administered and only consented clients were enrolled in the study. Standard sample collection criteria were used for all collected samples subjected to standard smear microscopy, Lowenstein Jensen culture and PCR studies. Results: Direct smear microscopy (AFB) was positive in 13 (13.5%), 24 (23.3%) were detected by PCR and 20 (19.4%) were culture positive. All positive smears were found to be positive for both culture and PCR. All culture positive samples were positive by PCR, culture growth were also positive by PCR. Most of the PCR results were ready within the first day of the analysis with average of 1.2 days (P = 0.014) of the 103 samples processed. The result of smear microscopy is only ready on the second day after analysis of the second and third samples submitted with reported average of 1.7 days (P = 0.035). The fastest observable growth of positive culture was seen only within ten days and only three cases showed such. It took eight weeks for a negative growth to be regarded as negative. The culture has an average tun around ti