COVID infection severity in children under 5 years old before and after Omicron emergence in the US
Year: 2022
Type: preprint
Study design: Observational Study
Abstract: Importance: Pediatric SARS-CoV-2 infections and hospitalizations are rising in the US and other countries after the emergence of Omicron variant. However data on disease severity from Omicron compared with Delta in children under 5 in the US is lacking. Objectives: To compare severity of clinic outcomes in children under 5 who contracted COVID infection for the first time before and after the emergence of Omicron in the US. Design Setting and Participants: This is a retrospective cohort study of electronic health record (EHR) data of 79,592 children under 5 who contracted SARS-CoV-2 infection for the first time, including 7,201 infected between 12/26/2021-1/6/2022 when the Omicron predominated (Omicron cohort), 63,203 infected between 9/1/2021-11/15/2021 when the Delta predominated (Delta cohort), and another 9,188 infected between 11/16/2021-11/30/2021 when the Delta predominated but immediately before the Omicron variant was detected in the US (Delta-2 cohort). Exposures: First time infection of SARS-CoV-2. Main Outcomes and Measures: After propensity-score matching, severity of COVID infections including emergency department (ED) visits, hospitalizations, intensive care unit (ICU) admissions, and mechanical ventilation use in the 3-day time-window following SARS-CoV-2 infection were compared between Omicron and Delta cohorts, and between Delta-2 and Delta cohorts. Risk ratios, and 95% confidence intervals (CI) were calculated. Results: Among 7,201 infected children in the Omicron cohort (average age, 1.49 ± 1.42 years), 47.4% were female, 2.4% Asian, 26.1% Black, 13.7% Hispanic, and 44.0% White. Before propensity score matching, the Omicron cohort were younger than the Delta cohort (average age 1.49 vs 1.73 years), comprised of more Black children, and had fewer comorbidities. After propensity-score matching for demographics, socio-economic determinants of health, comorbidities and medications, risks for severe clinical outcomes in the Omicron cohort were significantly lower than those in the Delta cohort: ED visits: 18.83% vs. 26.67% (risk ratio or RR: 0.71 [0.66-0.75]); hospitalizations: 1.04% vs. 3.14% (RR: 0.33 [0.26-0.43]); ICU admissions: 0.14% vs. 0.43% (RR: 0.32 [0.16-0.66]); mechanical ventilation: 0.33% vs. 1.15% (RR: 0.29 [0.18-0.46]). Control studies comparing Delta-2 to Delta cohorts show no difference. Conclusions and Relevance: For children under age 5, first time SARS-CoV-2 infections occurring when the Omicron predominated (prevalence >92%) was associated with significantly less severe outcomes than first-time infections in similar children when the Delta variant predominated.
Source: medRxiv
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: green
Awards: G1273157147, Combine computational prediction, network analysis and genetic screening in C elegans to uncover neurodegenerative causes in Alzheimer's Disease, Construct large-scale phenomes of disease and drugs and develop data-driven systems approaches to understand genetic links between Alzheimer's disease and Neuropsychiatric symptoms, G4637436490, G5742630968, G5822270753, G6182527505, Characterize multifaceted interactions between COVID-19 and alcohol use disorder based on real-time analysis of electronic health records of 62 million adult patients, An Integrated Reverse Engineering Approach Toward Rapid drug Re positioning for Alzheimer's Disease, Case Comprehensive Cancer Center (Case CCC) Cancer Health Disparities SPORE Planning Grant, Clinical and Translational Science Collaborative of Cleveland, Clinical and Translational Science Collaborative of Northern Ohio, Catalyzing Linkages for Everyone's Health (CLE Health), Case Comprehensive Cancer Center Support Grant, Case CCC Youth Engaged in Science, 09/01/2022-08/31/2027, Greater Southern California Node of the Clinical Trials Network
OpenAlex ID: W4206781002