ABSTRACT
Objective: To compare the efficiency of conventional diagnostic techniques and Insertion Sequence [IS]6110 based PCR assay for M. tuberculosis in pulmonary and extra-pulmonary specimens from tertiary care chest hospital
Study Design: Observational study
Place and Duration of Study: This study was conducted at Gulab Devi Chest Hospital, Lahore from August to January 2013
Materials and Methods: A total of 1599 [1417 pulmonary and 182 extra-pulmonary] non-duplicate clinical specimens, obtained over a period of six months, were tested by conventional techniques such as Ziehl-Neelsen staining [ZN], Lowenstein Jensen [LJ] medium and Fluorescent staining. MTB was extracted through DNAzol method. Insertion Sequence [IS] 6110 based PCR assay was used for M. tuberculosis from pulmonary and extra-pulmonary specimens. Of the 1599 specimens, 781 were suspect cases while 818 were MDR [follow up] cases. Mean age of TB patient was +/- 33 years. 18% of follow-ups and 20% of suspects were <20 year in age, 52% follow-ups and 36% suspects were about 20-40 years, and 30% follow-ups and 33% suspects were >40 years ofage
Results: It was seen that, among MDR cases [follow-ups] 68% were males and 32% were females. Similarly,among TB-suspects, 58% were males and 42% were females. Of total 168 suspected pulmonary samples ZN [48.2.7%], fluorescent microscopy [79.7%], LJ culture [52.9%] and PCR [91.6%] were positive for M. tuberculosis. In total 143 suspected extra-pulmonary samples, ZN [34.95%], fluorescent microscopy [45.5%], LJ culture [39.8%] and PCR [87.4%] werepositive
Conclusion: In contrast to conventional methods of TB diagnosis, PCR is more quick, sensitive, reliable and cost effective technique