ABSTRACT
Background & objectives: A combination of resistant and susceptible Mycobacterium tuberculosis (MTB) isolated from clinical specimens is referred to as heteroresistance. Heteroresistance leads to difficulties in drug resistance testing and may adversely affect treatment outcomes. The present study estimated the proportion of heteroresistance among MTB in clinical samples of presumptive drug-resistant tuberculosis (TB) patients in Central India. Methods: A retrospective analysis of data generated from line probe assay (LPA) at a tertiary care hospital in Central India between January 2013 and December 2018 was carried out. A heteroresistant MTB in a sample was indicated by the presence of both wild-type and mutant-type patterns on an LPA strip. Results: Data analysis was carried out on interpretable 11,788 LPA results. Heteroresistance in MTB was detected in 637 (5.4%) samples. Of these, heteroresistance in MTB was detected in 413 (64.8%), 163 (25.5%) and 61 (9.5%) samples with respect to rpoB, katG and inhA genes, respectively. Interpretation & conclusions: Heteroresistance is considered a preliminary step in the development of drug resistance. Delayed or suboptimal anti-tubercular therapy in patients with heteroresistance of MTB may elicit full clinical resistance and negatively impact the National TB Elimination Programme. Further studies are, however, needed to determine the impact of heteroresistance on treatment outcomes in individual patients.
ABSTRACT
Global efforts are being made to eliminate tuberculosis (TB) as a public health problem by 2030. These efforts are being thwarted by the challenge of effective management to minimise the progression of latent TB infection (LTBI) to TB, thereby interrupting the chain of transmission. Approximately 5%–10% LTBI cases eventually develop TB in their lifetime with the risk being higher in children, people living with HIV/AIDS (PLHIV), undernourished people, and patients with diabetes, chronic kidney disease, silicosis, and other comorbid conditions. Apart from operational barriers, complex ethical issues govern decision-making processes in either retaining current LTBI management practices or advocating implementation of the latest World Health Organization guidelines, which suggest extending treatment to vulnerable groups who have a higher risk of progression to TB. Newer LTBI treatment regimens have a diminished risk of toxicity that allays threats to patient safety. Public health justification for treating LTBI can also override patient autonomy, but the lack of a patient-centred approach is associated with poor adherence and treatment outcomes. Cost-effectiveness studies need to evaluate the gains and losses accruing from funding treatment of LTBI versus similar costs in nutritional interventions for managing undernutrition. Similarly, the impact of diverting resources available for management of the existing active TB control programmes to expanding LTBI treatment also needs to be assessed. In conclusion, a comprehensive LTBI treatment strategy built on the basis of high-quality evidence is the best way forward for resolving the ethical considerations at the heart of LTBI management in the developing world. Keywords: Tuberculosis; India; Latent TB; Medical ethics
ABSTRACT
Medical college faculty, who are academicians are seldom directly involved in the implementation of national public health programmes. More than a decade ago for the first time in the global history of tuberculosis (TB) control, medical colleges of India were involved in the Revised National TB Control Programme (RNTCP) of Government of India (GOI). This report documents the unique and extraordinary course of events that led to the involvement of medical colleges in the RNTCP of GOI. It also reports the contributions made by the medical colleges to TB control in India. For more than a decade, medical colleges have been providing diagnostic services (Designated Microscopy Centres), treatment [Directly Observed Treatment (DOT) Centres] referral for treatment, recording and reporting data, carrying out advocacy for RNTCP and conducting operational research relevant to RNTCP. Medical colleges are contributing to diagnosis and treatment of human immunodeficiency virus (HIV)-TB co-infection and development of laboratory infrastructure for early diagnosis of multidrug-resistant and/or extensively drug-resistant TB (M/XDR-TB) and DOTS-Plus sites for treatment of MDR-TB cases. Overall, at a national level, medical colleges have contributed to 25 per cent of TB suspects referred for diagnosis; 23 per cent of ‘new smear-positives’ diagnosed; 7 per cent of DOT provision within medical college; and 86 per cent treatment success rate among new smear-positive patients. As the Programme widens its scope, future challenges include sustenance of this contribution and facilitating universal access to quality TB care; greater involvement in operational research relevant to the Programme needs; and better co-ordination mechanisms between district, state, zonal and national level to encourage their involvement.