RT Journal Article
SR Electronic
T1 Performance of Xpert MTB/RIF Ultra for tuberculosis diagnosis in the context of passive and active case finding
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 2100257
DO 10.1183/13993003.00257-2021
VO 58
IS 6
A1 Belén Saavedra
A1 Edson Mambuque
A1 Dinis Nguenha
A1 Neide Gomes
A1 Shilzia Munguambe
A1 Juan Ignacio García
A1 Santiago Izco
A1 Sozinho Acacio
A1 Adrià Murias-Closas
A1 Marta Cossa
A1 Irene Losada
A1 Hadrián Pernas-Pardavila
A1 Laura Oliveras
A1 Grant Theron
A1 Alberto L. García-Basteiro
YR 2021
UL http://erj.ersjournals.com/content/58/6/2100257.abstract
AB Aims We present a field evaluation of the diagnostic accuracy of Xpert MTB/RIF (“Xpert”) and Xpert MTB/RIF Ultra (“Ultra”) using two cohorts in a high tuberculosis/HIV burden setting in Southern Mozambique.Methods Single respiratory specimens from symptomatic adults accessing healthcare services (passive case finding (PCF) cohort) and from household and community close contacts (active case finding (ACF) cohort) were tested by smear microscopy, culture, Xpert and Ultra. Liquid and solid culture served as a composite reference standard. We explored the impact of trace results on specificity via their recategorisation to negative (in all and just among those previously treated individuals).Results 1419 and 252 participants were enrolled in the PCF and ACF cohorts, respectively. For the PCF cohort, Ultra showed higher sensitivity than Xpert overall (0.95 (95% CI 0.90–0.98) versus 0.88 (96% CI 0.82–0.93); p<0.001) and among smear-negative patients (0.84 (96% CI 0.71–0.93) versus 0.63 (96% CI 0.48–0.76)). Ultra's specificity was lower than Xpert's (0.96 (96% CI 0.95–0.97) versus 0.98 (96% CI 0.97–0.99); p=0.008). For ACF, sensitivities were the same (0.67 (95% CI 0.22–0.96) for both tests), although Ultra detected a higher number of microbiologically confirmed samples than Xpert (4.7% (12 out of 252) versus 2.7% (seven out of 252)). Conditional recategorisation of trace results among previously treated participants maintained differences in specificity in the PCF cohort.Conclusion These results add evidence on the improved sensitivity of Ultra and support its use in different case finding scenarios.Ultra has higher sensitivity and lower specificity than Xpert for passive case finding. Lower specificity estimates do not seem to be driven by false-positive results among previously treated participants. https://bit.ly/3wcsg62