FIND and partners have developed a simple Stool Processing Kit (SPK) that will enable processing of large numbers of stool samples, removal of PCR inhibitors which can be used at level 1 health facilities in low and middle income countries.~The SPK is not a diagnostic kit as such but rather a sample processing method. This study aims to determine the sensitivity and specificity of Xpert Ultra MTB/RIF (Ultra) combined with SPK for TB detection using microbiological confirmation on respiratory specimens (defined as: sputum, nasopharyngeal aspirate, and/or gastric aspirate) as the reference standard. We will further evaluate operational characteristics, including implementation considerations that will be needed for the potential roll out of the SPK.~Additionally, a comparison of the performance of the SPK with up to two other cnetrifuge-free stool processing methods will be done on the same stool samples. The first is a method developed by researchers at the KNCV Tuberculosis Foundation (Single One Step Stool) which does not require any additional reagents other than the Ultra Sample Reagent. The second is a method developed by the Paediatric Asian African Network for Tuberculosis and HIV Research (PAANTHER) group, the Optimized Sucrose Flotation method. Another diagnostic candidate, the urine Fujifilm SILVAMP TB LAM (FujiLAM) test will be assessed during the study.~Therefore, if the sensitivity of any of these tests is shown to be promising this may support further research and provide other alternatives to respiratory samples.
This is a prospective, multicentre cohort study in which the accuracy and the diagnostic yield of the Stool Processing Kit (SPK) in combination with Xpert Ultra MTB/RIF (Ultra) on stool samples will be assessed using a microbiological reference standard and a composite reference standard among children with signs and symptoms of pulmonary tuberculosis.