Clinical characteristics and risk factors of severe COVID-19 in hospitalized neonates with Omicron variant infection: a retrospective study

Abstract

Abstract Background Previous study on coronavirus disease 2019 (COVID-19) in neonates was limited, especially in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) Omicron variant. This study aims to analyze the clinical characteristics and identify risk factors associated with severe COVID-19 in neonates infected with Omicron variant. Methods The study population was neonates with COVID-19 who were admitted to The Affiliated Children’s Hospital of Xi’an Jiaotong University in northwest China, from December 10, 2022 to January 20, 2023. Chinese Center for Disease Control and Prevention (CDC) announced that all local COVID-19 cases were infected with Omicron variant during the study period. Clinical and laboratory data was collected retrospectively. We used logistic regression analysis to investigate the risk factors for severe COVID-19, and derived odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) from it. Results A total of 108 neonates have a median age of 18.1 days (interquartile range 9.4–23.0) for diagnosis of COVID-19 including 84 in mild group and 24 in severe group. Of them, 6.5% were premature and 22.2% had severe infection. There were no deaths. The most common clinical manifestations were fever (88.9%) and cough (55.6%), with 5 cases (4.6%) complicated by pneumonia. 4 cases (3.7%) received respiratory support, including 2 cases of high-flow oxygen and 2 cases of non-invasive ventilation. Gestational age at birth (OR: 0.615; 95% CI: 0.393–0.961), neutrophil count (NEU) (OR:0.576; 95% CI : 0.344–0.962) and lymphocyte count (LYM) (OR: 0.159; 95% CI: 0.063–0.401) were independent risk factors for severe COVID-19. The combination of NEU and LYM had the largest receiver operating characteristic area under the curve [0.912 (95% CI:0.830–0.993)] for identifying severe COVID-19, with a sensitivity of 0.833 and a specificity of 0.917. Conclusions The general presentations and outcomes of neonatal COVID-19 caused by Omicron variant were not severe and very few patients required respiratory support. The simultaneous decrease in NEU and LYM can be used to identify severe infection.