OBJECTIVES: The purposes of this study were to describe the clinical characteristics of febrile infants younger than 90 days with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, to investigate the prevalence of serious bacterial infections (SBIs) in these infants, and to compare the risk of SBI in SARS-CoV-2-positive febrile infants with sex- and age-matched SARS-CoV- 2-negative febrile infants. METHODS: This was a retrospective cohort study conducted from March to November 2020 in a tertiary children's hospital. Patients were identified by International Classification of Diseases, 10th Revision codes and included if age was younger than 90 days, a SARS-CoV-2 test was performed, and at least 1 bacterial culture was collected. Positive cases of SARS-CoV-2 were age- and sex-matched to negative controls for analysis. Serious bacterial infection was defined as a urinary tract infection, bacterial enteritis, bacteremia, and/or bacterial meningitis. RESULTS: Fifty-three SARS-CoV-2-positive infants were identified with a higher rate of respiratory symptoms and lower white blood cell and C-reactive protein values than their SARS-CoV-2 matched controls. The rate of SBI in the SARS-CoV-2-positive infants was 8% compared with 34% in the controls; the most common infections were urinary tract infections (6% vs 23%). There were no cases of bacteremia or bacterial meningitis in the COVID-19 (coronavirus disease 2019) infants and 2 (4%) cases of bacteremia in the controls. The relative risk of any SBI between the 2 groups was 0.22 (95% confidence interval, 0.1-0.6; P &#8804; 0.001). CONCLUSIONS: These results suggest that febrile infants younger than 90 days with COVID-19 have lower rates of SBI than their matched SARS-CoV-2-negative controls. These data are consistent with previous studies describing lower risks of SBI in febrile infants with concomitant viral respiratory tract infections.
Risk of Serious Bacterial Infections in Young Febrile Infants With COVID-19