Paper Title
Prevalence of Primary & Secondary Multi Drug Resistant (MDR-TB) in & Around Aligarh Region, India

Introduction: Tuberculosis is an infectious bacterial disease caused by Mycobacterium tuberculosis which most commonly affects the lungs. It is transmitted from person to person via droplets from the throat and lungs of people with active pulmonary disease [1]. TB is a serious global public health threat. TB is the ninth leading cause of death worldwide and the leading cause from a single infectious agent, ranking above HIV/ AIDS [2]. In 2016, there were an estimated 1.3 million TB deaths among HIV negative and an additional 374 000 deaths among HIVpositive people [2]. Globally in 2016, an estimated 4.1% of new cases and 19% of previously treated cases had Multidrug resistant TB [2]. Rapid identification is important for effective treatment and control of MDR-TB. Conventional methods of drug susceptibility testing (DST) include solid media-based methods such as the proportion, absolute concentration, and resistance ratio methods. These can take up to 12 weeks to produce definitive results, leading to prolonged infectiousness [3]. Liquid media-based tests are more rapid, but also costlier and require sophisticated laboratories and trained personnel [3]. Molecular LPA permit rapid diagnosis of TB, isoniazid and rifampin resistance, and clinically relevant non-M. tuberculosis mycobacteria. In LPA assays, DNA or RNA is isolated from culture or direct (i.e., sputum) respiratory samples and then amplified and reverse hybridized onto a nitrocellulose strip with immobilized probes for different mycobacteria or for mutations that confer resistance. These strips can be quickly interpreted using a template, with the entire testing process taking a day or even less. The GenoType MTBDRplus (Hain Lifesciences, Nehren, Germany) identifies rifampin and isoniazid resistance by detecting the most common mutations of the rpoB gene and the katG and inhA genes, respectively. Materials and Methods: Sputum samples from 1588 suspected pulmonary TB patients were collected and subjected to ZN microscopy and fluorescent microscopy and cultured on LJ media. Sputum positive samples were tested by LPA for the presence of M. tuberculosis complex and resistance to isoniazid and rifampicin. LPA: The GenoType MTBDRplus LPA was performed according to the manufacturer’s (Hain Life-science, Nehren, Germany) instructions. Three steps for LPA test include DNA extraction, multiplex polymerase chain reaction (PCR) amplification and reverse hybridization. These steps were carried out in three separate rooms with restricted access and unidirectional workflow. LPA strips were observed and read for the presence of TUB band, amplification control band and conjugation control band and absence of any wild type (WT) band or presence of any mutation (MUT) band. The results were then interpreted as sensitive or resistant to any particular drug. Results: Out of 1558 sputum samples from MDR-TB suspected patients, 514 (32.9%) were suspected primary MDR-TB and 1074 (68.9%) were from previously treated cases. Flourescent microscopy positive samples were 942 of which 326 (34.6%) were new cases and 616 (65.3%) were from previously treated cases. 895 samples were TUB band positive. Among the new cases 47 (9.14%) samples were resistant to Rifampicin & Isoniazid (MDR-TB) and among the previously treated cases they were 115 (10.7%). Whereas monoresistance to Rifampicin among primary TB and secondary TB cases was 21 (4.08%) and 38 (3.54%). Similarly monoresistance to Isoniazid among new and previously treated cases was 31 (6.03%) and 59 (5.49%). Results were obtained within 48 hours of sample receiving by LPA. Conclusions: The present study shows that resistance to Rifampicin & Isoniazid (MDR-TB) is high both as primary or secondary MDR tuberculosis. Delay in diagnosis of MDR-TB poses threat of greater transmission and spread. Rapid detection of MDR-TB by Line Probe Assay will provide better control and initiation of early treatment of MDR-TB. Keywords - MDR-TB, LPA