ABSTRACT
Background: Prompt and accurate diagnosis of multi drug resistant tuberculosis is essential to avoid unnecessary delay in treatment. The conventional methods for testing drug susceptibility requires 4-6 weeks for isolation of Mycobacterium tuberculosis and another 4-5 weeks for testing susceptibility thus delaying the diagnosis and treatment
Objectives: To validate the drug susceptibility testing of isoniazid and rifampicin with Genotype MTBDRplus kit and comparing with the conventional standard drug proportion method. Study type, settings and duration: This cross sectional study was carried out in PMRC TB Research Centre, King Edward Medical University Mayo Hospital Lahore in collaboration with Shaukat Khanum Memorial Cancer Hospital and the Research Centre from November 2008 to October 2009
Materials and Methods: A total of 77 AFB smear positive and negative specimens from adult patients suffering from pulmonary and extra pulmonary TB were included in this study. Samples were processed for drug sensitivity testing by drug proportion method using Lowenstein Jensen medium and also on Genotype MTBDRplus assay
Results: Out of 77 specimens 74% were pulmonary and 26% extra pulmonary. There were 29 females and 48 males with a mean age was 30 years. Culture positivity on LJ medium was 69% while that on MTB PCR was 79%. Out of 53 culture positive specimens, 8[15%] were MDR while out of 61 MTB PCR positive specimens 9[14.7%] were MDR
Conclusion: Genotype MTBDRplus assay, is a highly sensitive technique for diagnosis of MDR TB in smear positive and smear negative complicated suspects; but it requires expensive instruments and skilled personnel