Using PCR Technque In Comparison With Other Tests In The Diagnosis Of Pulmonary TB Associated With Mycotic Infections In AL-Qadisiya Province.

Abstract

Background: Tuberculosis (TB) remains an important public health problem world wide. It is one of the leading infectious diseases in the world and is responsible for more than 3 million deaths and 8 million new cases annually.The report of World Health Organization (WHO) estimated, for the year 2002 a global incidence of 8.8 million new cases, including 3.9 million smear-positive
subjects.
Aim of the study: We aimed to evaluate the effectiveness of available rapid diagnostic tests to identify TB infection.  The main goal of this study was to use the PCR technique for the rapid detection of tuberculosis using sputum sampling and body fluid specimens other than respiratory secretions.
Methods: During the period from December 2006 to May 2007, A total of 50 samples (sputum) were selected from 250 outpatients.The study regard's the culture of sputum as the gold standard test to other methods.
Results:All of the examined patients with TB, the cause was M. tuberculosis.Clinical and laboratory diagnosis of the suspected patients revealed that 30 patients were suffering from PMIs , 15 of them had mixed infection.Twenty patients appeared to have pulmonary tuberculosis without mycotic infection. The sensitivity, specificity, PPV, NPV and Accuracy rate of PCR test were (94.2 %, 100%, 100%, 88.2% and 96 %), respectively.
Conclusions: The AFB stain was easy but not sufficient to diagnosis the pulmonary TB alone, whereas the use of LÖwenstein-Jensen medium sensitive enough for diagnosis of pulmonary TB, but need along time to get the results. The polymerase chain reaction (PCR) test gave a high sensitivity and specificity in comparison with other done test, with its advantages of greater speed and effectiveness than conventional detection methods. It was successfully to identify the M. tuberculosis, particularly when the staining for acid- fast bacilli is negative and there was a lack of growth on culture or when fresh material has not been collected for culture.