Thorax
Volume 65, Issue 5, 2010, Pages 442-448

A prospective large-scale study of methods for the detection of latent Mycobacterium tuberculosis infection in refugee children (Article) (Open Access)

Lucas M.* , Nicol P. , McKinnon E. , Whidborne R. , Lucas A. , Thambiran A. , Burgner D. , Waring J. , French M.
  • a Department of Clinical Immunology, Royal Perth Hospital, Pathwest Laboratory Medicine, Perth, WA, Australia
  • b School of Paediatrics and Child Health, University of Western Australia, Perth, WA, Australia
  • c Centre for Clinical Immunology and Biomedical Statistics, Murdoch University, Perth, WA, Australia
  • d Department of Clinical Immunology, Royal Perth Hospital, Pathwest Laboratory Medicine, Perth, WA, Australia
  • e Centre for Clinical Immunology and Biomedical Statistics, Murdoch University, Perth, WA, Australia
  • f Migrant Health Unit, North Metropolitan Area Health Service, Perth, WA, Australia
  • g Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, VIC, Australia
  • h TB Control Program, North Metropolitan Area Health Service, Perth, WA, Australia
  • i School of Pathology and Laboratory Medicine, University of Western Australia, Perth, WA, Australia

Abstract

Background: Diagnosis of latent tuberculosis infection (LTBI) is a cornerstone of the health assessment of resettled high incidence populations, particularly in children. Two blood-based interferon g release assays (IGRAs), T-SPOT.TB and QFT-Gold in-tube (QFT-GIT), have greater sensitivity and specificity than the tuberculin skin test (TST), but their performance as screening tools for LTBI in children, especially refugee children, remains unclear. Methods: 524 African and ethnic Burmese children, including 107 under 3 years of age, were prospectively enrolled in a comparison of the T-SPOT.TB and QFT-GIT. The TST was also performed in 342 of the children. Results: The T-SPOT.TB and QFT-GIT had similar rates of positivity (8% and 10%, respectively) and showed good concordance when both tests gave definitive results (κ=0.78; p<0.0001). However, the IGRAs had significant failure rates: 15% of QFT-GIT gave indeterminate results due to failed mitogen response and 14% of T-SPOT.TB results were inconclusive, largely because of insufficient mononuclear leucocyte yields. Failure of the QFT-GIT mitogen response was associated with African ethnicity and co-morbid infections, particularly with helminths. The TST results showed poor concordance (∼50%) with both IGRAs. Conclusions: It is reasonable to screen using either IGRA with follow-up by the alternative if the test fails. In general, the QFT-GIT is the preferred option for non-African populations but the T-SPOT.TB is recommended when there are epidemiological and/or clinical high risk factors for TB infection. However, both IGRAs have methodological and performance characteristics that limit their usefulness in refugee children, highlighting the need for continued development of screening strategies.

Author Keywords

[No Keywords available]

Index Keywords

prospective study helminth refugee follow up human comorbidity controlled study Mycobacterium tuberculosis priority journal screening test school child Adolescent male preschool child female tuberculosis Infant Africa diagnostic test high risk population Myanmar sensitivity and specificity Article major clinical study tuberculin test blood analysis t spot tb assay quantiferon tb gold in tube assay enzyme linked immunospot assay ethnicity Child
Link
https://www.scopus.com/inward/record.uri?eid=2-s2.0-77951990998&doi=10.1136%2fthx.2009.127555&partnerID=40&md5=0d6b779a8babb153cef2486f857590e6
DOI: 10.1136/thx.2009.127555
ISSN: 00406376
Cited by: 47
Original Language: English