Study of prevalence Rifampicin and/ or Isoniazid drug resistance among newly diagnosed cases of sputum smear positive pulmonary tuberculosis at tertiary care centre

Introduction: Worldwide tuberculosis is most common infectious cause of death. India bears one-fourth of the global tuberculosis burden. Despite all national & international efforts to control & eliminate tuberculosis, more than 10 million active tuberculosis cases occur each year. The problem of tuberculosis has been further compounded by the emergence of multi drug resistant (MDR) and extensively drug resistant(XDR) tuberculosis. Previously treated tuberculosis is most important risk factor for drug resistant TB but treatment naı̈ve patients are also at risk due to transmission of drug resistant strain or spontaneous mutation. Materials and Methods: Study was conducted in Department Of Respiratory Medicine, GMC Nagpur between May 2017 to October 2018.It was prospective observational study. All sputum smear positive cases were subjected to mycobacterial culture and LPA testing in IRL. Results: Total 250 patients whose sputum smear was positive for acid fast bacilli were included in study. Maximum patients were in age group of 18-30 years of age with mean age 36.43+/-14.05.Out of 250 patient 188 were males and 62 were females. Isoniazid monoresistance was found in 6 patients and isoniazid with rifampicin resistance was found in 9 patients. We did not find any case of rifampicin monoresistance in our study. Conclusion: Prevalence of isoniazid monoresistance was 2.4 % in our study while prevalence of isoniazid and rifampicin resistance (MDR TB) was 3.6%. Thus prevalence of drug resistant TB is low amongst newly diagnosed sputum smear positive cases. This shows success of tuberculosis control programme. © 2020 Published by Innovative Publication. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by/4.0/)


Introduction
Drug-resistant pulmonary tuberculosis (DR-TB) is a major public health problem that considerably affects the present TB control programme in India. Tuberculosis (TB) control efforts are threatened by the emergence of Mycobacterium tuberculosis strains that are resistant to first-line and second line drugs. In 2017, TB was responsible for an estimated 1.3 million deaths among HIV-negative people, and an additional 300 000 deaths from TB among HIVpositive people. There were an estimated 10.0 million new cases of TB, equivalent to 133 cases per 100 000 population. Globally in 2017, there were an estimated 558 000 new cases of rifampicin resistant TB (RR-TB), of which almost half were in three countries: India (24%), China (13%) and the Russian Federation (10%). Among RR-TB cases, an estimated 82% had multidrug-resistant TB (MDR-TB). Globally, 3.5% of new TB cases and 18% of previously treated cases had MDR/RR-TB, with the highest proportions (>50% in previously treated cases) in countries of the former Soviet Union. Previous treatment for TB is the most important risk factor for development of MDR-TB, but naïve patients are also at risk due to either spontaneous mutations or transmission of drug-resistant strains. 1 The https://doi.org/10.18231/j.ijmmtd.2020.008 2581-4753/© 2020 Innovative Publication, All rights reserved. 39 risk of transmission of resistant strains from close contacts is increasing because of the growing burden of MDR-TB patients. Therefore, there is high likelihood that what initially seems to be drug-sensitive TB in a treatment-naïve patient might in fact be MDR TB. Therefore, there is a need to determine the prevalence of MDR-TB among new cases of sputum-positive pulmonary TB

Materials and Methods
This study was conducted in department of respiratory medicine , Government medical college , Nagpur which is also a nodal DR TB centre attached to IRL.

Study design
Hospital based prospective observational study

Study sample
All the patients presenting to or referred to Respiratory Medicine OPD at tertiary care center as a newly diagnosed case of sputum AFB smear positive pulmonary tuberculosis.

Study period
May 2017 to October 2018

Sampling method
The patients selected were newly diagnosed sputum AFB smear positive pulmonary tuberculosis from outpatient and inpatient of department of Respiratory Medicine of same institute. The study was carried out after approval from the institutional ethical committee and with fully informed and written consent from the subjects. All sputum smear positive cases were subjected to mycobacterial culture and LPA testing in IRL.

Statistical Analysis
Data was entered in Microsoft excel 2010 and analysed. The proportions of study variables were calculated and expressed in terms of percentages.

Results
Maximum patients were in age group of 18-30 years followed by 31-40 years Almost all patient had BMI less than 25 which suggest undernutrition.

Drug resistance pattern
6 patient had only isoniazid resistance while 9 patients were positive for both isoniazid and rifampicin resistance.

Discussion
The present study was prospective observational study conducted in department of respiratory medicine, Government medical college, Nagpur to find out prevalence of drug resistance in newly diagnosed sputum smear positive cases. The most cost effective measure to treat the drug susceptible tuberculosis is provision and implementation of good quality DOTS thereby preventing the spread of  4 There were greater number of male patients than female patients in this study with 75.2% males and 24.8% females ( Figure 2). These results were similar with studies by SK Sharma et al 5 Jethani S etal. 6 In this study, about 86% patients were malnourished (Figure 3),12.8% patients were in the normal range, 1.2% were pre obese, with median BMI (15.38 +/-3.51). Kasim M et al 7 studied the nutritional status and body mass index of pulmonary tuberculosis patients and found that mean BMI of pulmonary tuberculosis cases was (16.9 ± 1.1kg/m2). Natasha S. Hochberg et al 8 found that 60.2% of tuberculosis patients were malnourished (body mass index [BMI] <18.5 kg/m2). We found 6 patients(2.4%) with isoniazid monoresistance and 9 patients (3.6%) with both isoniazid and rifampicin resistance (Figure 4). This results are comparable with Indian national figures of 2.84 % of primary MDR TB per PMDT guiselines 2017. 9 While prevalence of isoniazid monoresistance was 11.6% in newly detected sputum smear positive patients as per 2017 PMDT guidelines, it was very low in our study(2.4%). This may be the result of timely diagnosis and treatment of tuberculosis and successful implementation of programme.

Source of funding
None.

Conflict of interest
None.