Severe Acute Respiratory Syndrome Coronavirus 2 in Infants Younger Than 90 Days Presenting to the Pediatric Emergency Department: Clinical Characteristics and Risk of Serious Bacterial Infection.

OBJECTIVES: There are scant data on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in infants younger than 90 days. This study was designed to characterize COVID-19 presentation and clinical course in this age group and evaluate the risk of serious bacterial infection. METHODS: Data on all SARS-CoV-2-polymerase chain reaction-positive infants presenting to the pediatric emergency department (PED) were retrospectively collected, followed by a case-control study comparing those infants presenting with fever (COVID group) to febrile infants presenting to the PED and found to be SARS-CoV-2 negative (control group). RESULTS: Of the 96 PCR-positive SARS-CoV-2 infants who met the inclusion criteria, the most common presenting symptom was fever (74/96, 77.1%) followed by upper respiratory tract infection symptoms (42/96, 43.8%). Four (4.2%) presented with symptoms consistent with brief resolved unexplained event (4.2%).Among the febrile infants, the presenting symptoms and vital signs were similar in the COVID and control groups, with the exception of irritability, which was more common in the control group (8% and 26%; P < 0.01). The SARS-CoV-2-positive infants had decreased inflammatory markers including: C-reactive protein (0.6 ± 1 mg/dL vs 2.1 ± 2.7 mg/dL; P < 0.0001), white blood cell count (9.3 ± 3.4 × 10 9 /L vs 11.8 ± 5.1 × 10 9 /L; P < 0.001), and absolute neutrophils count (3.4 ± 2.4 × 10 9 /L vs 5.1 ± 3.7 × 10 9 /L; P < 0.001). The rate of invasive bacterial infection was similar between groups (1.4% and 0%; P = 0.31). No mortality was recorded. Although not significantly different, urinary tract infections were less common in the COVID group (7% and 16%; P = 0.07). CONCLUSIONS: The SARS-CoV-2 infection in infants aged 0 to 90 days who present to the PED seems to be mostly mild and self-limiting, with no increased risk of serious bacterial infection.

Return Visits in Infants Younger Than 90 Days Presenting to the Pediatric Emergency Department for Fever.

Fever in infants presenting to pediatric emergency departments (PEDs) often results in significant return visits (RVs). This retrospective study aimed to identify factors associated with RVs in febrile infants aged 0 to 90 days. Data from infants presenting to PED between 2018 and 2021 and returning within 7 days (RV group) were compared to age-matched febrile infants without RVs (control group). Each group had 95 infants with similar demographics and medical history. RVs were primarily due to positive cultures and persistent fever. The control group had higher initial hospitalization rates, longer PED stays, and increased antibiotic treatment. Prevalence of serious bacterial infections (SBIs) did not significantly differ. Higher hospitalization, prolonged PED stays, and initial antibiotic treatment were associated with reduced RV incidence despite similar SBI rates. Return visits in infants <90 days were primarily driven by persistent fever and positive cultures. Addressing these factors through targeted parental education and improved care protocols may reduce RVs.