Tuberculosis screening for pediatric household contacts in India: Time to adapt newer strategies under the National TB Elimination Programme!

INTRODUCTION: The study aimed to evaluate the effectiveness of screening pediatric household contacts (under the age of 15 years) for tuberculosis (TB) in India through verbal screening, tuberculin skin testing, and chest radiography at intervals of 0, 3, 6, 9, and 12 months. The study also aimed to determine the proportion of contacts who tested positive for TB and to describe the challenges in implementing regular follow-up. Current National TB Elimination Programme (NTEP) guidelines only require verbal screening for contacts under 6 years old at TB treatment initiation. The study aimed to fill this knowledge gap and provide valuable insights for improving TB screening in pediatric household contacts in India. METHODS: The study was conducted in two districts of Karnataka, India from 2021 to 2022, and utilized a cohort study design to enroll contacts of index tuberculosis (TB) cases diagnosed under the National TB Elimination Programme (NTEP). Participants were followed up at regular intervals for one year to evaluate the effectiveness of TB screening in pediatric household contacts. RESULTS: In this study, 686 pediatric household contacts were enrolled and screened for tuberculosis (TB) using verbal symptom screening, tuberculin skin testing (TST), and chest radiography. Projected figures estimated that 0.8%, 42%, and 4% of contacts would test positive for symptomatic screening, TST, and chest radiography, respectively. TB cases were detected in 2.91% (1.84-4.38) of contacts, with females above 6 years of age having a 22% higher risk of contracting the infection than males above 6 to < 15 years. However, not all cases were subjected to TST and chest radiography. The primary reason for not investigating child contact for TB was their reported healthy or asymptomatic status. CONCLUSION: The implementation of regular screening intervals for tuberculin skin test (TST) and chest radiography, along with verbal screening, among pediatric household contacts under the age of 15 years seems to be beneficial for the National TB Elimination Programme (NTEP), despite the challenges faced during implementation. Innovative strategies should be explored by NTEP to ensure effective implementation.

Challenges Perceived by Health Care Providers for Implementation of Contact Screening and Isoniazid Chemoprophylaxis in Karnataka, India.

Background: In India, challenges in pediatric TB contact screening and chemoprophylaxis initiation are still underexplored. Elucidating these challenges will help in better implementation of the programme at the grass-roots level thereby helping in early detection of pediatric cases and timely initiation of preventive therapy. This study aimed at exploring the challenges faced by the health care provider in contact screening and chemoprophylaxis initiation implementation of the pediatric household contacts. Methods: A qualitative study was conducted in the districts of Bengaluru and Udupi and in-depth interviews of key participants were adopted to explore the challenges. Qualitative data analysis was done after developing transcripts by generating themes and codes. Results: The key challenges were identified as stigma towards the disease, migrant patients with changing address, difficulty in sample collection, anxiety among parents due to long duration of the prophylactic treatment and adherence to IPT is not well documented, inadequate transportation from rural areas, and the ongoing COVID-19 pandemic. Conclusions: It is important for the National TB programme to address these challenges efficiently and effectively. Innovative solutions, feasible engagements, and massive efforts are to be taken by the programme to improve contact screening and isoniazid chemoprophylaxis implementation.

Influence of Single Nucleotide Polymorphisms on Rifampin Pharmacokinetics in Tuberculosis Patients.

Rifampin (RF) is metabolized in the liver into an active metabolite 25-desacetylrifampin and excreted almost equally via biliary and renal routes. Various influx and efflux transporters influence RF disposition during hepatic uptake and biliary excretion. Evidence has also shown that Vitamin D deficiency (VDD) and Vitamin D receptor (VDR) polymorphisms are associated with tuberculosis (TB). Hence, genetic polymorphisms of metabolizing enzymes, drug transporters and/or their transcriptional regulators and VDR and its pathway regulators may affect the pharmacokinetics of RF. In this narrative review, we aim to identify literature that has explored the influence of single nucleotide polymorphisms (SNPs) of genes encoding drug transporters and their transcriptional regulators (SLCO1B1, ABCB1, PXR and CAR), metabolizing enzymes (CES1, CES2 and AADAC) and VDR and its pathway regulators (VDR, CYP27B1 and CYP24A1) on plasma RF concentrations in TB patients on antitubercular therapy. Available reports to date have shown that there is a lack of any association of ABCB1, PXR, CAR, CES1 and AADAC genetic variants with plasma concentrations of RF. Further evidence is required from a more comprehensive exploration of the association of SLCO1B1, CES2 and Vitamin D pathway gene variants with RF pharmacokinetics in distinct ethnic groups and a larger population to reach conclusive information.