Pooled testing of sputum with Xpert MTB/RIF and Xpert Ultra during tuberculosis active case finding campaigns in Lao People's Democratic Republic
Iem, Vibol (Liverpool School of Tropical Medicine)
Chittamany, Phonenaly (National Tuberculosis Control Center (Vientiane, Laos))
Suthepmany, Sakhone (National Tuberculosis Control Center (Vientiane, Laos))
Siphanthong, Souvimone (National Tuberculosis Control Center (Vientiane, Laos))
Siphanthong, Phitsada (National Tuberculosis Control Center (Vientiane, Laos))
Somphavong, Silaphet (Center of Infectology Lao Christophe Merieux (Vientiane, Laos))
Kontogianni, Konstantina (Liverpool School of Tropical Medicine)
Dodd, James (Liverpool School of Tropical Medicine)
Khan, Jahangir A. M. (University of Gothenburg)
Domínguez, José (Institut Germans Trias i Pujol)
Wingfield, Tom (Liverpool School of Tropical Medicine)
Creswell, Jacob (Stop TB Partnership)
Cuevas, Luis E. (Liverpool School of Tropical Medicine)
Universitat Autònoma de Barcelona

Date:	2022
Abstract:	Active case finding (ACF) of individuals with tuberculosis (TB) is a key intervention to find the 30% of people missed every year. However, ACF requires screening large numbers of individuals who have a low probability of positive results, typically <5%, which makes using the recommended molecular tests expensive. We conducted two ACF surveys (in 2020 and 2021) in high TB burden areas of Lao PDR. Participants were screened for TB symptoms and received a chest X-ray. Sputum samples of four consecutive individuals were pooled and tested with Xpert Mycobacterium tuberculosis (MTB)/rifampicin (RIF) (Xpert-MTB/RIF) (2020) or Xpert-Ultra (2021). The agreement of the individual and pooled samples was compared and the reasons for discrepant results and potential cartridge savings were assessed. Each survey included 436 participants, which were tested in 109 pools. In the Xpert-MTB/RIF survey, 25 (sensitivity 89%, 95% CI 72. 8% to 96. 3%) of 28 pools containing MTB-positive samples tested positive and 81 pools containing only MTB-negative samples tested negative (specificity 100%, 95% CI 95. 5% to 100%). In the Xpert-Ultra survey, all 32 (sensitivity 100%, 95% CI 89. 3% to 100%) pools containing MTB-positive samples tested positive and all 77 (specificity 100%, 95% CI 95. 3% to 100%) containing only MTB-negative samples tested negative. Pooling with Xpert-MTB/RIF and Xpert-Ultra saved 52% and 46% (227/436 and 199/436, respectively) of cartridge costs alone. Testing single and pooled specimens had a high level of agreement, with complete concordance when using Xpert-Ultra. Pooling samples could generate significant cartridge savings during ACF campaigns.
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Xpert MTB/RIF ; Xpert Ultra ; Pooling ; Pooled testing ; Active case finding
Published in:	BMJ Global Health, Vol. 7 Núm. 2 (february 2022) , ISSN 2059-7908

DOI: 10.1136/bmjgh-2021-007592
PMID: 35165095

8 p, 1.1 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Health sciences and biosciences > Institut d'Investigació en Ciencies de la Salut Germans Trias i Pujol (IGTP)
Articles > Research articles
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