Although tuberculosis (TB) is treatable and preventable, it can be difficult to diagnose in children, according to the World Health Organization. TB is usually diagnosed using respiratory samples, such as sputum, a nasal wash, or sampling of stomach contents, 42 Technology (42T) shared in a news release. Collecting such samples, however, can involve unpleasant, invasive procedures, making it difficult to get samples from children.
Stool is the ideal noninvasive sample, but extensive pre-processing has been needed for analysis in highly sensitive PCR tests. 42T, FIND (the global alliance for diagnostics), and Rutgers University set out to determine whether stool samples and an automated PCR test could be used as a viable alternative to smear microscopy and culture techniques when diagnosing children.
Three different sample-processing methods were trialed by multiple research institutions in the past three years. After the data was pooled, WHO recommended that stool should now be used as the primary sample for TB diagnosis in children up to 10 years old, according to the release.
42T, FIND, and Rutgers devised a solution that processes stool samples without the need for any specialist laboratory equipment or technical skills. It works in conjunction with the Cepheid Xpert MTB/RIF ultra assay, which was codeveloped by David Alland’s team at Rutgers, FIND, and others. (Cepheid has been in the news for its EUA for a molecular test designed for use on the GeneXpert system that can detect viruses causing COVID-19, flu, and RSV infections.)
“Diagnosing pediatric TB is a major challenge requiring fresh thinking, because traditional samples for TB testing just aren’t accessible from young children,” stated Morten Ruhwald, head of TB at FIND, in the release from 42T. “Stool is so easy to collect from almost anyone—so being able to use that to test for TB is a major step forward. FIND was pleased to work with 42T and other partners to help generate crucial data for the WHO review, and we warmly welcome the update to the guidelines.”
Added Sarah Knight, 42T's head of healthcare technology: "Large-scale trials have shown the kit to be both effective and easy to use in a variety of settings. And we’re pleased that it has helped to inform the WHO in making its ground-breaking policy update on diagnosing childhood TB.”