Evaluation of Commercial Real Time PCR and Immunochromatography Techniques in Laboratory Diagnosis of Tuberculosis

Abstract

This study is a diagnostic evaluation study to real time PCR and Immunochromatography compared to conventional microbiological techniques (represented by Acid fast smear and culture) in laboratory diagnosis of tuberculosis. Whole blood and sputum samples were collected from 136 tuberculosis patients, 124 of them were pulmonary tuberculosis and 12 of them were extrapolmonary tuberculosis in addition to 102 healthy control subjects at consultant clinic for respiratory diseases in Hilla – Babil province-Iraq, during the period from May 2010 to June 2011. Real-time PCR kits, Immunochromatography rapid test in addition to acid fast smear and Lowenstein-Jensen culture were used to diagnose the tuberculosis cases. The results show that the sensitivities of the AFB smear, culture, RT-PCR and ICG were 74%, 43% 88% and 24%, respectively. The sensitivity of 99% was obtained by using RT-PCR and/or AFB smear as a diagnostic criteria. The specificity of AFB smear, culture, RT-PCR was 100%, while the specificity of ICG was 98%. The using of both AFB smear and RT-PCR as diagnostic tests raised the sensitivity to 99% compared with the using of the AFB smear, culture and ICG as a single test