CBNAAT Based Identification and Demographic Pattern of Drug Resistant Mycobacterium Tuberculosis in South Kashmir, India- a One Year Retrospective Study

India is the highest TB burden country in the world having an estimated incidence of 26.9 lakh cases in 2019. With a population of 1.32 billion, India has the highest burden of drug resistant TB (DR-TB) in the world. North zone of India is the second highest MDR-TB prevalent zone after the West zone of India. MDR TB treatment involves prolonged treatment with injectable second-line drugs, associated with more adverse effects, suboptimal treatment outcomes and higher risks of mortality compared to patients with drug-sensitive TB and those with lesser resistant forms of TB.

Materials methods: This retrospective study was conducted in the department of Microbiology Government Medical College Anantnag, data was analyzed from March 2017 to February 2018. Non-sterile specimens were processed by Modified Petroff Method. Sterile specimens were concentrated by centrifugation and smear and cultures was inoculated from the sediment. CBNAAT assay was performed by Gene Xpert (Cepheid) 4 system according to the manufacturers’ recommendations.

Results: Of the total 1497 clinically suspected tuberculosis specimens collected, 1370 (91.5%) were pulmonary and 127 (8.5%) were presumptive extra pulmonary tuberculosis received from different anatomical sites. Maximum clustering of cases was seen in 10-20 years age group. Out of the total 1497 samples 200 were CBNAAT confirmed Mycobacterium Tuberculosis positive samples. In which 155 were pulmonary and 45 were extra pulmonary. The average percentage positivity rate (i.e. percentage of MTB positive samples out of total samples tested) was 13.3% (200/1497). Rifampicin resistance (RR-TB) was seen in 5.5% (11/200) samples. Out of the samples detected positive (200): 155 were pulmonary samples and out of these 155 pulmonary samples 8 were found to be RR MTB 5.1% (8/155). Also out of the 200 positive samples 45 were extra pulmonary and out of these 45 extra pulmonary samples 3 were found to be RR MTB 6.6% (3/45).

Conclusion: In this study we found that in our region 5.5% cases of TB were RR-TB, 3.2% were new cases and 13% RR-TB was seen in previously treated cases of MTB. The screening of drug resistance has to be expanded to offer universal DST including expanded DST .The second and most important activity is to strengthen drug resistance surveillance under the various national programs with inclusion of laboratories in the private sector as well. The state level regional studies also give us the opportunity to plan and execute intervention prioritization, based on the drug resistance trends observed.