tetano
Editor, Senior Moderator
Pediatr Infect Dis J
. 2026 Sep 10.
doi: 10.1097/INF.0000000000005396. Online ahead of print.
Costanza Di Chiara 1 2 , Daniel S Farrar 2 , Julie A Bettinger 3 4 , Aaron Campigotto 5 , Olivier Drouin 6 7 , Joanne Embree 8 9 , Scott A Halperin 10 , Taj Jadavji 11 , Kescha Kazmi 1 , Jesse Papenburg 12 13 , Rupeena Purewal 14 , Manish Sadarangani 3 4 , Laura Sauvé 3 4 , Karina A Top 15 , Fatima Kakkar 16 , Shaun K Morris 1 2 17 18 ; for Members of the Canadian Immunization Monitoring Program, Active (IMPACT) COVID-19 Study
Affiliations Expand
Background: Co-circulation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with other respiratory viruses raised concerns that coinfections may increase pediatric coronavirus disease 2019 (COVID-19) severity, but evidence is limited by variable testing practices. We assessed the epidemiology and outcomes of SARS-CoV-2 respiratory viral coinfections in hospitalized children.
Methods: We analyzed national surveillance data from the Canadian Immunization Monitoring Program, ACTive (IMPACT) COVID-19 study. Children aged <17 years hospitalized with confirmed COVID-19 during Delta and Omicron periods were included. Coinfection was defined as SARS-CoV-2 plus ≥1 additional respiratory virus. Primary analyses were restricted to centres with systematic multiplex polymerase chain reaction (PCR) testing of all admissions with acute respiratory illness (n = 5), while secondary analyses included all centres (n = 13). Associations with outcomes (respiratory support, ventilation, intensive care and severe COVID-19) were estimated using multivariable mixed-effects logistic regression and adjusted odds ratios (aORs).
Results: Among 2831 hospitalized children, 938 were admitted at centers with systematic multiplex PCR testing, among whom 18.6% had ≥1 respiratory viral coinfection. Respiratory syncytial virus (39.7%) and enterovirus/rhinovirus (38.5%) coinfections were the most common. Coinfections were not associated with increased odds of severe COVID-19 in centers with systematic multiplex PCR testing (aOR 0.94; 95% confidence interval, 0.76-1.15). In secondary analyses including all centers irrespective of testing strategy, coinfections were associated with increased odds of severe COVID-19 (aOR 1.42; 95% confidence interval, 1.05-1.91).
Conclusions: In centers that systematically conducted multiplex PCR testing, SARS-CoV-2 respiratory viral coinfections were not associated with increased COVID-19 severity. Differences observed when including centers without systematic testing underscore the importance of considering testing strategies when evaluating the clinical impact of coinfections.
Keywords: COVID-19; children; coinfection; severity; testing practice.
. 2026 Sep 10.
doi: 10.1097/INF.0000000000005396. Online ahead of print.
SARS-CoV-2 Coinfections and Severity in Hospitalized Children With Systematic Testing
Costanza Di Chiara 1 2 , Daniel S Farrar 2 , Julie A Bettinger 3 4 , Aaron Campigotto 5 , Olivier Drouin 6 7 , Joanne Embree 8 9 , Scott A Halperin 10 , Taj Jadavji 11 , Kescha Kazmi 1 , Jesse Papenburg 12 13 , Rupeena Purewal 14 , Manish Sadarangani 3 4 , Laura Sauvé 3 4 , Karina A Top 15 , Fatima Kakkar 16 , Shaun K Morris 1 2 17 18 ; for Members of the Canadian Immunization Monitoring Program, Active (IMPACT) COVID-19 Study
Affiliations Expand
- PMID: 42717388
- DOI: 10.1097/INF.0000000000005396
Abstract
Background: Co-circulation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with other respiratory viruses raised concerns that coinfections may increase pediatric coronavirus disease 2019 (COVID-19) severity, but evidence is limited by variable testing practices. We assessed the epidemiology and outcomes of SARS-CoV-2 respiratory viral coinfections in hospitalized children.
Methods: We analyzed national surveillance data from the Canadian Immunization Monitoring Program, ACTive (IMPACT) COVID-19 study. Children aged <17 years hospitalized with confirmed COVID-19 during Delta and Omicron periods were included. Coinfection was defined as SARS-CoV-2 plus ≥1 additional respiratory virus. Primary analyses were restricted to centres with systematic multiplex polymerase chain reaction (PCR) testing of all admissions with acute respiratory illness (n = 5), while secondary analyses included all centres (n = 13). Associations with outcomes (respiratory support, ventilation, intensive care and severe COVID-19) were estimated using multivariable mixed-effects logistic regression and adjusted odds ratios (aORs).
Results: Among 2831 hospitalized children, 938 were admitted at centers with systematic multiplex PCR testing, among whom 18.6% had ≥1 respiratory viral coinfection. Respiratory syncytial virus (39.7%) and enterovirus/rhinovirus (38.5%) coinfections were the most common. Coinfections were not associated with increased odds of severe COVID-19 in centers with systematic multiplex PCR testing (aOR 0.94; 95% confidence interval, 0.76-1.15). In secondary analyses including all centers irrespective of testing strategy, coinfections were associated with increased odds of severe COVID-19 (aOR 1.42; 95% confidence interval, 1.05-1.91).
Conclusions: In centers that systematically conducted multiplex PCR testing, SARS-CoV-2 respiratory viral coinfections were not associated with increased COVID-19 severity. Differences observed when including centers without systematic testing underscore the importance of considering testing strategies when evaluating the clinical impact of coinfections.
Keywords: COVID-19; children; coinfection; severity; testing practice.