Viral cultures, cycle threshold values and viral load estimation for assessing SARS-CoV-2 infectiousness in haematopoietic stem cell and solid organ transplant patients: a systematic review.

Autor: Jefferson T; Department for Continuing Education, University of Oxford, Oxford, UK., Spencer EA; Centre for Evidence-Based Medicine, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK., Conly JM; Departments of Medicine, Microbiology, Immunology & Infectious Diseases, and Pathology & Laboratory Medicine, Synder Institute for Chronic Diseases and O'Brien Institute for Public Health, Cumming School of Medicine, University of Calgary and Alberta Health Services, Calgary, Canada., Rosca EC; Victor Babes University of Medicine and Pharmacy, Timisoara, Romania., Maltoni S; Division of Research and Innovation, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy., Brassey J; Trip Database Ltd, Newport, UK., Onakpoya IJ; Department for Continuing Education, University of Oxford, Oxford, UK., Evans DH; Li Ka Shing Institute of Virology and Department of Medical Microbiology & Immunology, University of Alberta, Edmonton, Canada., Heneghan CJ; Centre for Evidence-Based Medicine, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK., Plüddemann A; Centre for Evidence-Based Medicine, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK. Electronic address: annette.pluddemann@phc.ox.ac.uk.
Jazyk: angličtina
Zdroj: The Journal of hospital infection [J Hosp Infect] 2023 Feb; Vol. 132, pp. 62-72. Date of Electronic Publication: 2022 Dec 05.
DOI: 10.1016/j.jhin.2022.11.018
Abstrakt: Background: Solid organ and haematopoietic stem cell transplant recipients are more vulnerable to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) than non-transplant recipients due to immunosuppression, and may pose a continued transmission risk, especially within hospital settings. Detailed case reports including symptoms, viral load and infectiousness, defined by the presence of replication-competent viruses in culture, provide an opportunity to examine the relationship between clinical course, burden and contagiousness, and provide guidance on release from isolation.
Objectives: To investigate the relationship between serial SARS-CoV-2 reverse transcription polymerase chain reaction (RT-PCR) cycle threshold (Ct) value or cycle of quantification value, or other measures of viral burden and the likelihood and duration of the presence of infectious virus based on viral culture, including the influence of age, sex, underlying pathologies, degree of immunosuppression, and/or vaccination on this relationship, in transplant recipients.
Methods: LitCovid, medRxiv, Google Scholar and the World Health Organization COVID-19 database were searched from 1 st November 2019 to 26 th October 2022. Studies reporting relevant data (results from serial RT-PCR testing and viral culture data from the same respiratory samples) for transplant recipients with SARS-CoV-2 infection were included in this systematic review: Methodological quality was assessed using five criteria, and the data were synthesized narratively and graphically.
Results: Thirteen case reports and case series reporting on 41 transplant recipients (22 renal, five cardiac, one bone marrow, two liver, one bilateral lung and 10 blood stem cell) were included in this review. A relationship was observed between proxies of viral burden and likelihood of shedding replication-competent SARS-CoV-2. Three individuals shed replication-competent viruses for >100 days after symptom onset. Lack of standardization of testing and reporting platforms precludes establishing a definitive viral burden cut-off. However, the majority of transplant recipients stopped shedding replication-competent viruses when the Ct value was >30 despite differences across platforms.
Conclusions: Viral burden is a reasonable proxy for infectivity when considered within the context of the clinical status of each patient. Standardized study design and reporting are essential to standardize guidance based on an increasing evidence base.
(Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)
Databáze: MEDLINE
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