Study of Antibiotic Susceptibility Pattern of Mycobacterium Tuberculosis in Pulmonary Tuberculosis Patients Visiting National Tuberculosis Center, Thimi, Bhaktapur, Nepal

Abstract

A study was conducted by Central Department of Microbiology, Tribhuwan University in collaboration with National Tuberculosis Center (NTC), Thimi, Bhaktapur, Nepal from September 2005 to May 2006 to study the anti-tuberculosis drugs susceptibility pattern of Mycobacterium tuberculosis isolated from the suspected pulmonary tuberculosis (PTB)patients visiting National Tuberculosis Center (NTC). The study included total 295 cases of pulmonary tuberculosis patients attending NTC.Among 295 cases, 250 cases were previously treated patients and 45 cases were untreated patients. The sputum samples were examined by auramine fluorochrome staining method and cultured on Ogawa media followed by biochemical tests (Niacin test, Nitratetest & Catalase test). Finally, Drug susceptibility testing was performed on lowenste in-Jensen media by Proportional Method. Among 295 PTB cases, 73.56% were males and 26.44% were females. According to drug sensitivity test, EMB (66.10%) was found to be the most effective drug followed by RMP(60.33%), SM (59.66%) and INH (41.69%) against Mycobacterium tuberculosis. The highest number of cases belonged to the age group 21-30 (28.81%). Among 45 isolates isolated from untreated patients, primary drug resistant to one drug in20%, to two drugs in 17.77%, to three drugsin 11.11%, to four drugs in 6.66% and primary multi-drug resistance in 22.22% of the total isolates. Among 250 isolates isolated from previously treated patients, acquired resistant to one drug was found in 23.60%, to two drugs in 12.40%, to three drugs in 16.40%, to four drugs in 18.80% and acquired multi-drugs resistance in 37.20% of the isolates. Among 250 treated cases, 68.4% were relapse,18% were chronic, 7.6% were follow-up, 3.2% were defaulted and 2.8% were treatment VII failure. MDR-TB was found the highest in chronic cases (64.44%) followed by follow-up cases (47.36%), treatment failure cases (42.85%), relapse cases (27.48%) and defaulted cases (12.5%). Only 150 culture positive cases were interviewed during the study. Among 150 culture positive isolates obtained from the interviewed PTB patients, 47.33% (n=71) were resistant and 52.66% (n=79) were sensitive. Out of 71 resistant isolates isolated from interviewed patients, 39.43% (n =28) had the habit of smoking, 35.21% (n=25) with habit of taking alcohol and 29.57% (n=21) had previous history of TB in their family. The habits of smoking, taking alcohol and having previous history of TB in their family were not significantly related with the development of drug resistance. Key words:M. tuberculosis, pulmonary tuberculosis, Drug susceptibility test, Proportion method, RMP, INH, EMB, SM, MDR-TB