Abstract
Background. Asymptomatic SARS-CoV-2 infection in children is highly prevalent but its acute and chronic implications have been minimally described. Methods. In this controlled case-ascertained household transmission study, we recruited asymptomatic children <18 years with SARS-CoV-2 nucleic acid testing performed at 12 tertiary care pediatric institutions in Canada and the United States. We attempted to recruit all test-positive children and 1 to 3 test-negative, site-matched controls. After 14 days' follow-up we assessed the clinical (ie, symptomatic) and combined (ie, test-positive, or symptomatic) secondary attack rates (SARs) among household contacts. Additionally, post-COVID-19 condition (PCC) was assessed in SARS-CoV-2-positive participating children after 90 days' follow-up. Results. A total of 111 test-positive and 256 SARS-CoV-2 test-negative asymptomatic children were enrolled between January 2021 and April 2022. After 14 days, excluding households with co-primary cases, the clinical SAR among household contacts of SARS-CoV-2-positive and -negative index children was 10.6% (19/179; 95% CI: 6.5%-16.1%) and 2.0% (13/663; 95% CI: 1.0%- 3.3%), respectively (relative risk = 5.4; 95% CI: 2.7-10.7). In households with a SARS-CoV-2-positive index child, age <5 years, being pre-symptomatic (ie, developed symptoms after test), and testing positive during Omicron and Delta circulation periods (vs earlier) were associated with increased clinical and combined SARs among household contacts. Among 77 asymptomatic SARS-CoV-2-infected children with 90-day follow-up, 6 (7.8%; 95% CI: 2.9%-16.2%) reported PCC. Conclusions. Asymptomatic SARS-CoV-2-infected children, especially those <5 years, are important contributors to household transmission, with 1 in 10 exposed household contacts developing symptomatic illness within 14 days. Asymptomatic SARS-CoV-2- infected children may develop PCC.
Original language | English (US) |
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Pages (from-to) | 1522-1530 |
Number of pages | 9 |
Journal | Clinical Infectious Diseases |
Volume | 78 |
Issue number | 6 |
DOIs | |
State | Published - Jun 15 2024 |
Funding
Potential conflicts of interest . A. F. reports grants from the University of Calgary Eyes High Postdoctoral Fellowship and Canadian Institutes of Health Research Banting Postdoctoral Fellowship, and support for meetings and/or travel from a Trainee Travel Grant (Pediatric Academic Societies and Trainee travel grant), Alberta Children's Hospital Association, University of Calgary. L. A. reports grants from Pfizer. M. W. reports support for meetings and/or travel from US Acute Care Solutions (USACS), stock and a board of directors position for EM Device Lab. N. K. reports a leadership or fiduciary role for the Pediatric Emergency Care Applied Research, Pediatric Emergency Research Network; research funding from the National Institutes of Health (NIH), Health Resources and Services Administration (HRSA), and Patient-Centered Outcomes Research Institute (PCORI). R. M. reports royalties or licenses for Affinivax; consulting fees from GSK, Affinivax, and Merck; payment for lectures and support for meetings and/or travel from GSK; patents planned, issued, or pending for Boston Children's Hospital; being a member of the Affinivax board of directors; and stock options for Affinivax and Corner Therapeutics. S. M. M. reports grants from Sanofi, Merck, Pfizer National Minority Quality Forum (US); support for meetings and/or travel from Sanofi, Merck, GSK, Pfizer, CSL, Biosciences Association of Manitoba (BAM), and the National Minority Quality Forum (US); and participation on a Data and Safety Monitoring Board or Advisory board for Sanofi. T. A. F. reports grants from the National Heart, Lung, and Blood Institute (NHLBI) and leadership or fiduciary roles for the Society of Pediatric Research and the Pediatric Academic Societies. 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. Financial support. This work was supported by the Canadian Institutes of Health Research (Operating Grant\u2014COVID-19 Rapid Research Funding Opportunity; A. F., T. A. F., N. K., S. B. F.) and the COVID-19 Research Accelerator Funding Track (CRAFT) Program at the University of California, Davis (N. K.). S. B. F. is supported by the Alberta Children's Hospital Foundation Professorship in Child Health and Wellness. A. F. was supported by a University of Calgary Eye's High Postdoctoral Research fund as well as a Canadian Institutes of Health Research Banting Postdoctoral Fellowship.
Keywords
- asymptomatic SARS-CoV-2
- children
- household transmission
- post-COVID-19 condition
- prospective cohort
ASJC Scopus subject areas
- Microbiology (medical)
- Infectious Diseases