Drug susceptibility patterns of the Mycobacterium tuberculosis isolated from previously treated and new cases of pulmonary tuberculosis at German-Nepal tuberculosis project laboratory, Kathmandu, Nepal

Abstract

BackgroundMultidrug resistant tuberculosis (MDR-TB) is a serious public health problem in Nepal. It is a major obstacle for the control of the tuberculosis. The main objectives of this study were to determine the prevalence of the multidrug resistant pulmonary tuberculosis and to evaluate the drug susceptibility patterns of Mycobacterium tuberculosis isolated from previously treated and newly diagnosed cases of pulmonary tuberculosis.MethodsA cross-sectional study was conducted from March 2013 to August 2013 at German-Nepal tuberculosis project (GENETUP) laboratory, Kathmandu, Nepal. For this the sputum samples from total of 153 (49 new and 104 previously treated) suspected pulmonary tuberculosis patients were used. The diagnosis of the tuberculosis was performed by using fluorescent microscopy and culture, while the drug susceptibility testing of Mycobacterium tuberculosis was performed by proportion method. Lowenstein-Jensen (L-J) medium was used for the culture of Mycobacterium tuberculosis and the colonies grown were identified on the basis of the colony morphology, pigment production and biochemical characteristics.ResultsThe prevalence of MDR-TB among all the cases of culture positive pulmonary tuberculosis was 15.6 %. The rate of MDR-TB among previously treated culture positive tuberculosis patients was 19.4 % and that among newly diagnosed culture positive pulmonary tuberculosis cases was 7.1 %. The highest rate of resistance of Mycobacterium tuberculosis, was toward streptomycin (24.4 %) followed by isoniazid (23 %), rifampicin (17.8 %) and ethambutol (15.6 %). Among the total of MDR-TB cases among previously treated patients, highest percentage of the cases were relapse (61.1 %) followed by chronic (16.7 %).ConclusionsThe high prevalence of DR/MDR-TB in our study reflects poor implementation of tuberculosis control program. On the basis of the drug susceptibility patterns of M. tuberculosis we found in our study, we recommend to include ethambutol instead of streptomycin in the multidrug therapy for the treatment of tuberculosis patients in Nepal. Further, due to high rate of MDR-TB among previously treated patients, we do not recommend to use first line drugs for the treatment of pulmonary tuberculosis among previously treated patients.

Drug Susceptibility Profile of Mycobacterium tuberculosis Isolated from Patients Visiting National Tuberculosis Centre, Nepal

“…Drug resistant cases detected in this study was less than the research conducted by Thapa et al (2016) in German-Nepal tuberculosis project laboratory which showed 31.1% of DR cases. Maharjan et al (2017) also noted 37.2% DR cases.The MDR strains prevalence in TB patients in this study was similar to previous studies (Thapa 2016;NTC 2016), but slightly higher than the research conducted in 2011 (7.9%) and 2015 (11.7%) (Maharjan et al 2017;Wagley et al 2016). This implies MDR strains prevalence in TB patients is continually increasing which poses a serious public health problem due to poor patient management, non-adherence to the prescribed regimen, irregular supply of drugs, poor quality of drugs and poor national TB control programme.…”

Use of GeneXpert for the diagnosis of multidrug resistant pulmonary tuberculosis among smear negative suspected tuberculosis cases in Nepal

“…Of 60 tuberculosis positive cases, 2 (3.33%) were MDR-TB cases. However, higher rate of MDR pulmonary tuberculosis was reported by Thapa et al (15.6 %) [6]. This may be because of including only smear negative suspected tuberculosis cases in our study.…”

Multi-drug resistant Mycobacterium tuberculosis in Port Harcourt, Nigeria

“…16 Other reported MDR tuberculosis rates from South East Asia include 15.6% from Nepal. 17 African countries are not among the top three countries associated with over half the global burden of MDR tuberculosis. 18 The MDR tuberculosis rates from this region have varied, with a range of rates reported: 4.5% from Chad, 19 12.0% from Benin, 20 5.1% from Mozambique, 21 18% from Cameroon, 22 11.5% from Djibouti, 23 and 1.2% and 3.37% from Ethiopia, 24,25 which are generally higher than the rate observed in this study.…”

“…Higher rates of MDR tuberculosis are generally reported in retreatment cases as opposed to newly diagnosed cases. 14,17,25,26…”