Risk factors for severe COVID-19 in hospitalized children in Canada: A national prospective study from March 2020--May 2021 (preprint)

Background: Children living with chronic comorbid conditions are at increased risk for severe COVID-19, though there is limited evidence regarding the risks associated with specific conditions and which children may benefit from targeted COVID-19 therapies. The objective of this study was to identify factors associated with severe disease among hospitalized children with COVID-19 in Canada. Methods: We conducted a national prospective study on hospitalized children with microbiologically confirmed SARS-CoV-2 infection via the Canadian Paediatric Surveillance Program from April 2020--May 2021. Cases were reported voluntarily by a network of >2800 paediatricians. Hospitalizations were classified as COVID-19-related, incidental infection, or infection control/social admissions. Severe disease (among COVID-19-related hospitalizations only) was defined as disease requiring intensive care, ventilatory or hemodynamic support, select organ system complications, or death. Risk factors for severe disease were identified using multivariable Poisson regression, adjusting for age, sex, concomitant infections, and timing of hospitalization. Findings: We identified 544 children hospitalized with SARS-CoV-2 infection, including 60{middle dot}7% with COVID-19-related disease and 39{middle dot}3% with incidental infection or infection control/social admissions. Among COVID-19-related hospitalizations (n=330), the median age was 1{middle dot}9 years (IQR 0{middle dot}1--13{middle dot}3) and 43{middle dot}0% had chronic comorbid conditions. Severe disease occurred in 29{middle dot}7% of COVID-19-related hospitalizations (n=98/330), most frequently among children aged 2-4 years (48{middle dot}7%) and 12-17 years (41{middle dot}3%). Comorbid conditions associated with severe disease included technology dependence (adjusted risk ratio [aRR] 2{middle dot}01, 95% confidence interval [CI] 1{middle dot}37-2{middle dot}95), neurologic conditions (e.g. epilepsy and select chromosomal/genetic conditions) (aRR 1{middle dot}84, 95% CI 1{middle dot}32-2{middle dot}57), and pulmonary conditions (e.g. bronchopulmonary dysplasia and uncontrolled asthma) (aRR 1{middle dot}63, 95% CI 1{middle dot}12-2{middle dot}39). Interpretation: While severe outcomes were detected at all ages and among patients with and without comorbidities, neurologic and pulmonary conditions as well as technology dependence were associated with increased risk of severe COVID-19. These findings may help guide vaccination programs and prioritize targeted COVID-19 therapies for children. Funding: Financial support for the CPSP was received from the Public Health Agency of Canada.

Clinical manifestations and disease severity of SARS-CoV-2 infection among infants in Canada (preprint)

ImportanceThere 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. ObjectiveThe 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. DesignProspective study of infants with SARS-CoV-2 from April 8th 2020 to May 31st 2021. SettingNational study using the infrastructure of the Canadian Paediatric Surveillance Program, reporting inpatients and outpatients seen in clinics and emergency departments. ParticipantsInfants <1 year of age with microbiologically confirmed SARS-CoV-2 infection. ExposureInfant-level characteristics associated with hospitalization for COVID-19. Main outcomes and MeasuresCases were classified as either: 1) Non-hospitalized patient with SARS-CoV-2 infection; 2) COVID-19-related hospitalization; or 3) non-COVID-19-related hospitalization (e.g., incidentally detected SARS-CoV-2). Case severity was defined as asymptomatic, outpatient care, mild (inpatient care), moderate or severe disease. Multivariable logistic regression was performed to identify characteristics associated with hospitalization. ResultsA 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 (aOR=4.53, 2.06-9.97), and infants <1 month had higher odds of hospitalization then infants aged 1-3 months (aOR=3.78, 1.97-7.26). In total, 20 infants (3.8%) met criteria for severe disease. Conclusions and RelevanceWe 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. Key PointsO_ST_ABSQuestionC_ST_ABSWhat are the spectrum of illness, disease severity, and characteristics associated with hospitalization in infants with SARS-CoV-2 infection? FindingsA total of 531 cases were reported to the Canadian Paediatric Surveillance Program, including 332 (62.5%) non-hospitalized and 199 (37.5%) hospitalized infants. In total, 20 infants met criteria for severe disease (3.8%). Infants characteristics associated with admission included age of less than one month and comorbid conditions. MeaningThis study provides data on the spectrum of disease, severity, and characteristics associated with admission due to COVID-19 in infants, which informs clinical management and public health interventions in this specific population.

Impact of the COVID-19 pandemic on the provision of routine childhood immunizations in Ontario, Canada (preprint)

BackgroundThe COVID-19 pandemic has a worldwide impact on all health services, including childhood immunizations. In Canada, there is limited data to quantify and characterize this issue. MethodsWe conducted a descriptive, cross-sectional study by distributing online surveys to physicians across Ontario. The survey included three sections: provider characteristics, impact of COVID-19 on professional practice, and impact of COVID-19 on routine childhood immunization services. Multivariable logistic regression identified factors associated with modification of immunization services. ResultsA total of 475 respondents answered the survey from May 27th to July 3rd 2020, including 189 family physicians and 286 pediatricians. The median proportion of in-person visits reported by physicians before the pandemic was 99% and dropped to 18% during the first wave of the pandemic in Ontario. In total, 175 (44.6%) of the 392 respondents who usually provide vaccination to children acknowledged a negative impact caused by the pandemic on their immunization services, ranging from temporary closure of their practice (n=18; 4.6%) to postponement of vaccines in certain age groups (n=103; 26.3%). Pediatricians were more likely to experience a negative impact on their immunization services compared to family physicians (adjusted odds ratio [aOR]=2.64, 95% CI: 1.48-4.68), as well as early career physicians compared to their more senior colleagues (aOR=2.69, 95% CI: 1.30-5.56), whereas physicians from suburban settings were less impacted than physicians from urban settings (aOR=0.62, 95% CI: 0.39-0.99). The most frequently identified barriers to immunizations during the pandemic were parental concerns around COVID-19 (n=305; 77.8%), lack of personal protective equipment (PPE; n=123; 31.3%) and healthcare workers concerns of contracting COVID-19 (n=105; 26.8%). ConclusionsCOVID-19 has caused substantial modifications to pediatric immunization services across Ontario. Strategies to mitigate barriers to immunizations during the pandemic need to be implemented in order to avoid immunity gaps that could lead to an increase in vaccine preventable diseases. HIGHLIGHTSO_LIWe have conducted a descriptive, cross-sectional study by distributing online surveys to pediatricians and family physicians across Ontario to assess the impact of the COVID-19 pandemic on their immunization practices. C_LIO_LIThe COVID-19 pandemic has caused a substantial decrease in in-person visits and a related disruption to routine childhood immunization services during the first wave of the pandemic. C_LIO_LIThe main barriers to immunizations during the pandemic included parents and healthcare providers concerns of contracting COVID-19, and lack of appropriate personal protective equipment (PPE). C_LIO_LISolutions to maintain childhood immunizations during the pandemic included assistance in providing PPE to clinical practices, dedicated centers for vaccination, and parental education. C_LI