DRUG RESISTANT TUBERCULOSIS AMONG PATIENTS IN CHEST UNIT OF MAYO HOSPITAL LAHORE.

Abstract

Background: Multidrug-resistant tuberculosis (MDR-TB) is an increasing serious global problem and has become all the more frightening over the last decade. Spread of MDR TB is through this repeated unsuccessful treatment and other strong reason is that patient who had no previous history of treatment and is infected with primary MDR TB bacilli from patient who had already developed MDR TB. In 1998, the global TB partners, including the WHO, created “DOTS PLUS” which attempted to address the most glaring deficiencies of DOTS especially regarding treatment of drug resistant TB.Objectives: To estimate the changing trends in drug resistant tuberculosis in patients visiting tertiary care settings.Study Settings: This descriptive study was carried out in Pakistan Medical Research Council TB Research Centre in collaboration with Department of Chest Medicine, King Edward Medical University. A total of 1013 cases were included; of which 899 were pulmonary and 114 extra pulmonary.Material and methods: Primary isolation of Mycobacterium was performed on Lowenstein Jensen (LJ) medium. Cultures grown were subjected to drug susceptibility testing on LJ. Medium containing drugs with the following concentrations using standard proportion method: RIF 40.0 μg/ml medium, INH 0.2 μg/ml, Streptomycin 4.0 μg/ml, Ethambutol 2.0 μg/ml. All the tubes were incubated at 37o C +/- 10 C for a minimum of four weeks. Any isolate giving more than 1% growth on the medium containing isoniazid, Ethambutol and rifampicin as compared with control was labeled as resistant strain. The critical proportion for resistance of streptomycin was 10%.Results: MDR TB was found to be in 16.58% of study subjects. Primary MDR TB was found in 12.83% and acquired was found in 24.18% cases. Mono resistance against Isoniazid, Rifampicin, Ethambutol and streptomycin was found in 6.12%, 6.81%, 2.6% and 2.15% respectively. Forty four percent cases were found to be resistant against at least one of the first line anti TB drugs and 2% cases were found to be resistant against all the four drugs included in this study.Conclusion: With the induction of “DOTS plus” strategy by TB Control program, MDR-TB is expected to go down. Comparing last five studies being conducted at PMRC TB Research Centre. It does not show any significant increase in drug resistance levels, from which we can conclude that drug resistance is leveling off.