Stool processing methods for xpert ultra testing in childhood tuberculosis: a prospective, multicountry accuracy study

2025

Article référencé dans le Web of Science WOS:001541486900001

Jaganath D., Nabeta P., Nicol M. P., Castro R., Wambi P., Zar H. J., Workman L., Lodha R., Singh U. B., Bavdekar A., Sanghavi S., Trollip A., Mace A., Bonnet Maryline, Lounnas Manon, de Haas P., Tiemersma E., Alland D., Banada P., Cattamanchi A., Ruhwald M., Wobudeya E., Denkinger C. M.

Clinical Infectious Diseases, 2025, [Early access], p. [9 p.] ISSN 1058-4838

Background Centrifuge-free processing methods support stool Xpert Ultra testing for childhood tuberculosis, but data on their accuracy, acceptability, and usability are limited.Methods We conducted a prospective evaluation of stool Xpert Ultra in India, South Africa, and Uganda with 3 methods: the Stool Processing Kit (SPK), the Simple One-Step method (SOS), and the Optimized Sucrose Flotation method (OSF). Children <15 years old with presumptive tuberculosis underwent sputum testing with Xpert Ultra and culture. We compared the accuracy of each method against a microbiological reference standard (tuberculosis if Xpert Ultra or culture positive) and a composite reference standard (tuberculosis if confirmed or unconfirmed tuberculosis). We surveyed laboratory staff to assess the acceptability and usability of the methods.Results We included 607 children, with a median age of 3.5 years (interquartile range, 1.3-7 years); 15.5% were human immunodeficiency virus positive. Against the microbiological reference standard, the sensitivities of SPK, SOS, and OSF were 36.9% (95% confidence interval, 28.6%-45.8%), 38.6% (17.2%-51.0%), and 31.3% (20.2%-44.1%), respectively, and the specificities, 98.2% (96.4%-99.3%), 97.3% (93.7%-99.1%), and 97.1% (93.3%-99%). The methods were acceptable and usable, but SOS was reported as most feasible to implement in a peripheral facility. Across methods, sensitivities increased among children who were culture positive (range, 55.0%-77.3%) and were low (13%-16.7%) against the composite reference standard. Adding stool Xpert Ultra increased sensitivity from 0% (OSF) to 11.8% (SPK/SOS), compared with sputum alone.Conclusions Stool processing methods for Xpert Ultra were acceptable and usable and performed similarly, with highest sensitivity among children with culture-positive tuberculosis.

Santé : généralités [050] ; Entomologie médicale / Parasitologie / Virologie [052]

Fonds IRD [F B010094444]

fdi:010094444