58 Clinical manifestations and disease severity of SARS-CoV-2 infection among infants in Canada

BACKGROUND: There are limited data on outcomes of SARS-CoV-2 infection among infants (<1 year of age). In the absence of approved vaccines for infants, understanding characteristics associated with hospitalization and severe disease from COVID-19 in this age group will help inform clinical management and public health interventions. OBJECTIVES: The objective of this study was to describe the clinical manifestations, disease severity, and characteristics associated with hospitalization among infants infected with the initial strains of SARS-CoV-2. DESIGN/METHODS: This is a nationwide prospective observational study using the infrastructure of the Canadian Paediatric Surveillance Program. All cases of infants aged <1 year of age with microbiologically confirmed SARS-CoV-2 infection were reported from April 8th 2020 to May 31st 2021, and were classified by disease severity and primary cause of hospitalization. Multivariable logistic regression was performed to identify infants' characteristics associated with hospitalization. RESULTS: A total of 531 cases were reported, including 332 (62.5%) non-hospitalized and 199 (37.5%) hospitalized infants. Among hospitalized infants, 141 of 199 infants (70.9%) were admitted because of COVID-19-related illness, and 58 (29.1%) were admitted for reasons other than acute COVID-19. Amongst all cases with SARS-CoV-2 infection, the most common presenting symptoms included fever (66.5%), coryza (47.1%), cough (37.3%) and decreased oral intake (25.0%). In our main analysis, infants with a comorbid condition had higher odds of hospitalization compared to infants with no comorbid conditions, and infants <1 month had higher odds of hospitalization than infants aged 1-3 months (Table). In total, 20 infants (3.8%) met criteria for severe disease. CONCLUSION: We describe one of the largest cohorts of infants with SARS-CoV-2 infection. Overall, severe COVID-19 in this age group is uncommon with most infants having mild disease. Comorbid conditions and younger age were associated with COVID-19-related hospitalization amongst infants. [Image: see text]