Presentations and Outcomes Among Infants ≤90 Days With and Without SARS-CoV-2.

OBJECTIVES:To compare symptoms and outcomes among infants aged ≤90 days tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a broad, international sample of emergency departments (EDs). METHODS:This was a secondary analysis of infants aged 0 to 90 days with suspected SARS-CoV-2 infections tested using molecular approaches and with 14-day follow-up. The parent studies were conducted at 41 EDs in 10 countries (the global Pediatric Emergency Research Network; March 2020-June 2021) and 14 EDs across Canada (Pediatric Emergency Research Canada network; August 2020-February 2022). Symptom profiles included presence and number of presenting symptoms. Clinical outcomes included hospitalization, ICU admission, and severe outcomes (a composite of intensive interventions, severe organ impairment, or death). RESULTS:Among 1048 infants tested for SARS-CoV-2, 1007 (96.1%) were symptomatic at presentation and 432 (41.2%) were SARS-CoV-2-positive. A systemic symptom (any of the following: Apnea, drowsiness, irritability, or lethargy) was most common and present in 646 (61.6%) infants, regardless of SARS-CoV-2 status. Although fever and upper respiratory symptoms were more common among SARS-CoV-2-positive infants, dehydration, gastrointestinal, skin, and oral symptoms, and the overall number of presenting symptoms did not differ between groups. Infants with SARS-CoV-2 infections were less likely to be hospitalized (32.9% vs 44.8%; difference -11.9% [95% confidence interval (CI) -17.9% to -6.0%]), require intensive care (1.4% vs 5.0%; difference -3.6% [95% CI -5.7% to -1.6%]), and experience severe outcomes (1.4% vs 5.4%; difference -4.0% [95% CI -6.1% to -1.9%]). CONCLUSIONS:SARS-CoV-2 infections may be difficult to differentiate from similar illnesses among the youngest infants but are generally milder. SARS-CoV-2 testing can help inform clinical management.