Comparison of GeneXpert MTB to Mycobacterium tuberculosis culture in children with tuberculosis

Abstract

Background Diagnosing tuberculosis (TB) in children is difficult. Typical methods take a long time to achieve results, or have a low sensitivity. GeneXpert is a nucleic acid amplification test used to identify Mycobacterium tuberculosis bacteria (MTB) in only 2 hours.
 Objective To compare the sensitivity and specificity of GeneXpert MTB to MTB culture in children with TB, and to assess factors associated with GeneXpert MTB test in predicting which children were likely to have positive results.
 Methods This descriptive, analytical study was done in children with suspected TB, aged 1 month to 18 years in Hasan Sadikin Hospital, Bandung, West Java, from January 2016 to December 2017. The data were taken from the medical records and included age, gender, nutritional status, symptoms of TB, chest x-ray, and tuberculin test results. The GeneXpert MTB test was compared to cultures from the same patient, with regards to sensitivity, specificity, and agreement using Kappa index. We analyzed factors associated to GeneXpert MTB test using logistic regression analysis.
 Results From 454 inpatients and 1,750 outpatients with suspected TB, there were 251 children who were tested by MTB culture and 722 children tested by GeneXpert MTB. Of the 70 cases who met the inclusion criteria and underwent both tests, factors associated with positive GeneXpert MTB results were age 10 to 18 years, female gender, and positive tuberculin skin test (TST). The GeneXpert MTB test showed sensitivity 78.9% (95%CI 56.7 to 91.5) and specificity 86.3% (95%CI 74.3 to 93.2), with accuracy of 84.3% (95%CI 74 to 91), and agreement value of ƙ=0.62 (95%CI 41.6 to 82.7).
 Conclusion Specificity of GeneXpert MTB is higher than its sensitivity compared to TB cultures in children. The tests were in good agreement. Age 10 to 18 years had the strongest association with positive GeneXpert MTB results.

Concordance of Sputum and Feces Samples for Detecting Mycobacterium Tuberculosis using Xpert® MTB/RIF Ultra

“…15,16 Notably, other studies have suggested that individuals aged 10 to 18 years are most strongly correlated with positive GeneXpert® MTB results. 17 DM emerged as the most prevalent comorbidity in our study. DM-TB patients with elevated and uncontrolled blood sugar levels face compromised immune systems, escalating the risk of TB treatment failure, severe complications, and a heightened mortality risk compared to those without comorbidities.…”

Trends in Rifampicin Resistance Among Children With Presumptive TB in the Pre-COVID and COVID-Era

“… 21 In contrast to the findings of this study, a report in Indonesia found that gender and age group were factors related to MTB detection. 22 Despite the adoption of the Xpert MTB/RIF test as the first line diagnostic, the poor detection rate for MTB may reflect the difficulty in diagnosing childhood TB. This also calls for greater study into the development of better diagnostic methods to improve case detection and prompt treatment for both drug-sensitive and drug-resistant tuberculosis in children.…”