Journal of the Association of Medical Microbiology and Infectious Disease Canada = Journal officiel de l'Association pour la microbiologie medicale et l'infectiologie Canada · 2024
Testing the limits of multiplex respiratory virus assays for SARS-CoV-2 at high cycle threshold values: Comparative performance of cobas 6800/8800 SARS-CoV-2 & Influenza A/B, Xpert Xpress SARS-CoV-2/Flu/RSV, and cobas Liat SARS-CoV-2 & Influenza A/B.
СтатьяНазвание и аннотация: Перевод в очереди
Обработка статьи · этапы, ошибки и управление
Загрузка состояния…
Ошибки и ограничения
История · было → стало
Состояние обновляется каждые 5 секунд, пока блок открыт. Процент показывается только там, где известен объём работы. Пауза останавливает продолжение этапа; текущий запрос к источнику может завершиться.
Matic Nancy, Lawson Tanya, Ritchie Gordon, Lowe Christopher F, Romney Marc G
Аннотация
BACKGROUND: Multiplex real-time RT-PCR assays for respiratory pathogens are valuable tools to optimize laboratory workflow and turnaround time. At a time when resurgence of influenza and respiratory syncytial virus (RSV) cases have been widely observed along with continued transmission of SARS-CoV-2, timely identification of all circulating respiratory viruses is crucial. This study evaluates the detection of low viral loads of SARS-CoV-2 by four multiplex molecular assays: Roche cobas 6800/8800 SARS-CoV-2 & Influenza A/B Test, Cepheid Xpert Xpress SARS-CoV-2/Flu/RSV, cobas Liat SARS-CoV-2 & Influenza A/B, and a laboratory-developed test (LDT).
METHODS: Retrospective upper respiratory tract specimens positive for various respiratory viruses at a range of cycle threshold (Ct) values (18-40) were tested by four multiplex assays. Positive and negative percent agreement (PPA and NPA) with validated RT-PCR assays were calculated.
RESULTS: A total of 82 samples were assessed, with discordant results observed in a portion of the samples (10/82, 12.2%) where Ct values were >33. The majority of the discordant results (6/10, 60%) were false negatives. Overall, PPA was 100% (58/58) for cobas 6800, 97.4% (38/39) for GeneXpert, 100% (17/17) for Liat, and 90.5% (57/63) for the LDT. PPA for the LDT increased to 92.1% after manual review of amplification curves.
CONCLUSIONS: Commercial multiplex respiratory virus assays have good performance for samples with medium to high viral loads (Ct values <33). Laboratories should consider appropriate test result review and confirmation protocols to optimize sensitivity, and may consider reporting samples with additional interpretive comments when low viral loads are detected.
METHODS: Retrospective upper respiratory tract specimens positive for various respiratory viruses at a range of cycle threshold (Ct) values (18-40) were tested by four multiplex assays. Positive and negative percent agreement (PPA and NPA) with validated RT-PCR assays were calculated.
RESULTS: A total of 82 samples were assessed, with discordant results observed in a portion of the samples (10/82, 12.2%) where Ct values were >33. The majority of the discordant results (6/10, 60%) were false negatives. Overall, PPA was 100% (58/58) for cobas 6800, 97.4% (38/39) for GeneXpert, 100% (17/17) for Liat, and 90.5% (57/63) for the LDT. PPA for the LDT increased to 92.1% after manual review of amplification curves.
CONCLUSIONS: Commercial multiplex respiratory virus assays have good performance for samples with medium to high viral loads (Ct values <33). Laboratories should consider appropriate test result review and confirmation protocols to optimize sensitivity, and may consider reporting samples with additional interpretive comments when low viral loads are detected.