Utility of Xpert MTB/RIF Assay for Diagnosis of Pediatric Tuberculosis Under Programmatic Conditions in India

Rakesh Yadav,Pankaj Vaidya,Joseph L Mathew,Sanjay Verma,Rajiv Khaneja,Priyanka Agarwal,Pankaj Kumar,Meenu Singh,Sunil Sethi

doi:10.2991/jegh.k.191215.002

Rakesh Yadav, Pankaj Vaidya + Show 7 more

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https://doi.org/10.2991/jegh.k.191215.002

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Abstract

Tuberculosis (TB) diagnosis in children still remains a challenge in developing countries. We analyze the performance of Xpert MTB/RIF assay for the diagnosis of pediatric TB under programmatic conditions. We retrospectively analyzed the performance of Xpert MTB/RIF assay from February 2016 to March 2018. A total 2678 samples from TB suspects below 14 years were received in the laboratory and were frontline tested by Xpert MTB/RIF assay according to the manufacturer’s instructions. If sample was sufficient, the smear microscopy and culture were performed as per standard World Health Organization’s guidelines. The smears and cultures were performed in 2178 and 588 samples, respectively. Among 2678 samples, 68 were rejected, Xpert MTB/RIF assay was positive in 357/2610 (13.6%) cases, while the smear was positive in 81/2178 (3.3%) cases. The sensitivity of smear and Xpert MTB/RIF when compared with culture was 24.6% (14.1–37.8%) and 81% (68.6–90.1%), respectively. The diagnostic accuracy of Xpert MTB/RIF and smear was 97.1% and 92.2%, respectively. Thirty samples (8.5%) were detected as rifampicin resistance by Xpert MTB/RIF assay. The Xpert MTB/RIF increased the detection rate up to fourfold when compared with smear microscopy. Xpert MTB/RIF assay is the most rapid, sensitive, and specific method for microbiological confirmation and rifampicin resistance detection in pediatric tuberculosis.

Highlights

Childhood tuberculosis (TB) constitutes a major but underappreciated burden of disease in endemic countries as the national TB programs mainly focus on adult TB [1,2]
These samples were first processed for Xpert MTB/RIF assay, and if the sample was sufficient, the other methods like smear microscopy and culture were performed
Thirty (8.5%) samples were found rifampicin resistant, of which there were 20 (2 bronchoalveolar lavage (BAL), 2 ET aspirate, 5 gastric lavage (GL), and 11 sputum) respiratory samples and 10 (3 cerebrospinal fluid (CSF), 2 fine needle aspiration cytology (FNAC), 1 LN aspirate, 1 pleural fluid, and 3 pus) were nonrespiratory samples

Summary

Introduction

Childhood tuberculosis (TB) constitutes a major but underappreciated burden of disease in endemic countries as the national TB programs mainly focus on adult TB [1,2]. Especially in children, the diagnosis of pediatric TB has become more complex because of limited World Health Organization (WHO) endorsed tests. Each test has its own limitations, for example, smear microscopy has a low sensitivity due to paucibacillary nature of TB in children and lacks reproducibility [5]. The gold standard for TB diagnosis is Mycobacterium tuberculosis culture, which is laborious and time consuming [6]. The sensitivity of culture for the diagnosis of pediatric TB, as comparison to clinical standard, ranges from 25 to 75% depending upon the specimen’s type, quality, and the severity of disease [6]

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