Incidence Rates of Medically Attended COVID-19 in Infants Less than 6 Months of Age

ObjectiveStudies suggest infants may be at increased risk of severe COVID-19 relative to older children, but few data exist regarding the incidence of COVID-19 episodes and associated risk factors. We estimate incidence rates and describe characteristics associated with medically attended COVID-19 episodes among infants younger than 6 months of age.MethodsWe analyzed electronic medical record data from a cohort of infants born March 1, 2020‒ February 28, 2021. Data from three health care delivery systems included demographic characteristics, maternal and infant outpatient visit and hospitalization diagnoses, and SARS-CoV-2 test results. Medically attended COVID-19 episodes were defined by positive SARS-CoV-2 clinical tests and/or COVID-19 diagnosis codes during medical care visits. Unadjusted and site-adjusted incidence rates by infant month of age, low and high SARS-CoV-2 circulation periods and maternal COVID-19 diagnosis were calculated.ResultsAmong 18,192 infants aged ConclusionMost medically attended COVID-19 episodes in infants aged Article SummaryThis report describes incidence rates and characteristics of medically attended outpatient and inpatient COVID-19 episodes among infants aged What’s Known on This SubjectSurveillance data and case series suggest that infants aged What this Study AddsAmong infants aged