Belén Saavedra1,2, Edson Mambuque1, Dinis Nguenha1, Neide Gomes1, Shilzia Munguambe1, Juan Ignacio García3, Santiago Izco1,2, Sozinho Acacio1, Adrià Murias-Closas2, Marta Cossa1, Irene Losada2, Hadrián Pernas-Pardavila4, Laura Oliveras2,5,6, Grant Theron7, Alberto L García-Basteiro8,2. 1. Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique. 2. ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain. 3. TB Group, Population Health Programme, Texas Biomedical Research Institute, San Antonio, TX, USA. 4. Infectious Diseases, Complexo Hospitalario Universitario de Santiago, Santiago de Compostela, Spain. 5. Agència de Salut Pública de Barcelona, Barcelona, Spain. 6. Institut d'Investigació Biomèdica Sant Pau (IIB Sant Pau), Barcelona, Spain. 7. DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research and SAMRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa. 8. Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique alberto.garcia-basteiro@manhica.net.
Abstract
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.
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.
Authors: Shima M Abdulgader; Anna O Okunola; Gcobisa Ndlangalavu; Byron W P Reeve; Brian W Allwood; Coenraad F N Koegelenberg; Rob M Warren; Grant Theron Journal: Respiration Date: 2022-06-27 Impact factor: 3.966
Authors: Ruvandhi R Nathavitharana; Alberto L Garcia-Basteiro; Morten Ruhwald; Frank Cobelens; Grant Theron Journal: EBioMedicine Date: 2022-03-23 Impact factor: 11.205