Clinical Severity of Severe Acute Respiratory Syndrome Coronavirus 2 Omicron Variant Relative to Delta in British Columbia, Canada: A Retrospective Analysis of Whole-Genome Sequenced Cases.

Autor:	Harrigan SP; British Columbia Centre for Disease Control, Vancouver, Canada.; Centre for Disease Control, University of British Columbia, Vancouver, Canada., Wilton J; British Columbia Centre for Disease Control, Vancouver, Canada., Chong M; British Columbia Centre for Disease Control, Vancouver, Canada., Abdia Y; British Columbia Centre for Disease Control, Vancouver, Canada., Velasquez Garcia H; British Columbia Centre for Disease Control, Vancouver, Canada., Rose C; British Columbia Centre for Disease Control, Vancouver, Canada.; School of Population and Public Health, University of British Columbia, Vancouver, Canada., Taylor M; British Columbia Centre for Disease Control, Vancouver, Canada., Mishra S; Department of Medicine, University of Toronto, Toronto, Canada.; MAP Centre for Urban Health Solutions, Li Ka Shing Knowledge Institute, Unity Health Toronto, Toronto, Canada.; Division of Epidemiology and Institute of Health Policy, Management and Evaluation, Dalla Lana School of Public Health, University of Toronto, Toronto, Canada.; Institute of Medical Science, University of Toronto, Toronto, Canada., Sander B; Toronto Health Economics and Technology Assessment Collaborative, Toronto General Hospital Research Institute, University Health Network, Toronto, Canada.; Institute of Health Policy, Management and Evaluation, Dalla Lana School of Public Health, University of Toronto, Toronto, Canada.; Public Health Ontario, Toronto, Canada.; Institute for Clinical Evaluative Sciences (ICES), Toronto, Canada., Hoang L; British Columbia Centre for Disease Control, Vancouver, Canada.; Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada., Tyson J; British Columbia Centre for Disease Control, Vancouver, Canada., Krajden M; British Columbia Centre for Disease Control, Vancouver, Canada.; Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada., Prystajecky N; British Columbia Centre for Disease Control, Vancouver, Canada.; Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada., Janjua NZ; British Columbia Centre for Disease Control, Vancouver, Canada.; School of Population and Public Health, University of British Columbia, Vancouver, Canada.; Centre for Health Evaluation and Outcome Sciences, St. Paul's Hospital, Vancouver, Canada., Sbihi H; British Columbia Centre for Disease Control, Vancouver, Canada.; School of Population and Public Health, University of British Columbia, Vancouver, Canada.
Jazyk:	angličtina
Zdroj:	Clinical infectious diseases : an official publication of the Infectious Diseases Society of America [Clin Infect Dis] 2023 Feb 08; Vol. 76 (3), pp. e18-e25.
DOI:	10.1093/cid/ciac705
Abstrakt:	Background: In late 2021, the Omicron severe acute respiratory syndrome coronavirus 2 variant emerged and rapidly replaced Delta as the dominant variant. The increased transmissibility of Omicron led to surges in case rates and hospitalizations; however, the true severity of the variant remained unclear. We aimed to provide robust estimates of Omicron severity relative to Delta. Methods: This retrospective cohort study was conducted with data from the British Columbia COVID-19 Cohort, a large provincial surveillance platform with linkage to administrative datasets. To capture the time of cocirculation with Omicron and Delta, December 2021 was chosen as the study period. Whole-genome sequencing was used to determine Omicron and Delta variants. To assess the severity (hospitalization, intensive care unit [ICU] admission, length of stay), we conducted adjusted Cox proportional hazard models, weighted by inverse probability of treatment weights (IPTW). Results: The cohort was composed of 13 128 individuals (7729 Omicron and 5399 Delta). There were 419 coronavirus disease 2019 hospitalizations, with 118 (22%) among people diagnosed with Omicron (crude rate = 1.5% Omicron, 5.6% Delta). In multivariable IPTW analysis, Omicron was associated with a 50% lower risk of hospitalization compared with Delta (adjusted hazard ratio [aHR] = 0.50, 95% confidence interval [CI] = 0.43 to 0.59), a 73% lower risk of ICU admission (aHR = 0.27, 95% CI = 0.19 to 0.38), and a 5-day shorter hospital stay (aß = -5.03, 95% CI = -8.01 to -2.05). Conclusions: Our analysis supports findings from other studies that have demonstrated lower risk of severe outcomes in Omicron-infected individuals relative to Delta. Competing Interests: Potential conflicts of interest . M. K. has grants and contracts with AbCellera (contract paid to institution), Roche, Hologic (contract paid to institution), and Siemens (contract paid to institution), all of which are unrelated to this study. N. Z. J. participates in an AbbVie Advisory Board meeting; reports payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing, or educational events from AbbVie; and reports grants or contracts unrelated to this work from the Canadian Institutes of Health Research, Michael Smith Foundation for Health Research, and Public Health Agency of Canada. H. S. reports grants or contracts unrelated to this work from the Canadian Institutes for Health Research. N. P. reports grants or contracts unrelated to this work from the Canadian Institutes for Health Research and Michael Smith Foundation for Health Research. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed. (© The Author(s) 2022. Published by Oxford University Press on behalf of Infectious Diseases Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
Databáze:	MEDLINE
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