New reference standards for TB diagnostics in children now published in JID
As has been highlighted on World TB day, children with TB are a neglected
population usually omitted from research in treatment and diagnostics.
Accurate diagnosis of Mycobacterium tuberculosis in children has long been
difficult and current diagnostic tools available fail to address the
problems experienced in diagnosing TB in children. With most tests relying
on sputum, which is often difficult to obtain in children and does not have
the same diagnostic yield as in adults, there is a desperate need for new
rapid, accurate diagnostic tests for children. The development of new tools
for children has been hampered by a lack of consensus on case definitions
for research purposes. A lack of reference standard contributes to the
hesitancy to enrol children in diagnostic research studies. They are
usually excluded from studies into new technologies and when they are
included, the lack of a clear reference standard has presented difficulties
comparing paediatric diagnostic studies due to the different methodologies
and case definitions used. Research into paediatric TB diagnostics is very
limited and a consensus on a reference standard should promote further
research and ensure that the maximum benefits can be gained from it.
The National Institute of Health sponsored a meeting in June 2011 “Critical
Issues in Paediatric Tuberculosis Diagnostics Research in HIV-Infected and
Uninfected Children”, bringing together a group of leading paediatric TB
experts. The meeting addressed the lack of an agreed reference standard for
diagnostics, and an expert consensus was reached on clinical case
definitions for intra-thoracic TB diagnosis in children. Consensus was also
reached on how to standardise methodological approaches for evaluation of
new TB diagnostic tests in children. The published consensus statements
clearly specify how to use these definitions to reliably classify a child
for research purposes.
With the development of these consensus guidelines and by encouraging their
widespread uptake, there is no longer an excuse to continue to exclude
children from TB diagnostic research. These guidelines help address the
urgent need to develop tests that can work in children, ideally using
non-sputum based samples, which benefit not only children but other
difficult to diagnose groups such as HIV co-infected patients. It is vital
that these reference standards are endorsed and implemented by the major
donors, researchers and diagnostic developers.
The consensus statements have been published this month in a JID
supplementary article, Evaluation of TB diagnostics in children: 1.
Proposed clinical case definitions for classification of intra-thoracic
tuberculosis disease in children. Consensus from an expert panel are
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