Clinical Characteristics of SARS-CoV-2 Omicron Infection in Children under One Year

Abstract

The United Kingdom has recorded a notable increase in SARS-CoV-2 cases across all age groups since December 2021, linked to the emergence of the SARS-CoV-2 Omicron variant. National data shows a recent increase in the number of confirmed SARS-CoV-2 cases and hospitalisations in children, particularly those aged <1 year. The case series comprised the first 55 chronologically-identified cases of Omicron infections in children under 1-year of age that were reported to the United Kingdom Health Security Agency (UKHSA). Secure contact was made with clinical leads in NHS provider trusts and clinical data were received on 45/55 infants admitted. The majority of cases 69% (38/55) occurred in infants 3 months or under. Length of stay ranged from 0 to 9 days with an average of 2 days, 6.7% (3/45) had an oxygen requirement, 4.4% (2/45) required ventilation (1 invasive and 1 non-invasive) and 51.1% (23/45) received medication. The most common reason(s) for admission were fever and/or respiratory symptoms (86%), five infants (11.1% [5/45]) had co-morbidities. The vast majority of patients in this case series presented with a short febrile illness, did not require significant medical intervention, all cases made a full recovery and were discharged. Infants with fever were treated in accordance with NICE guidelines. In this short case series no adverse outcomes were identified with Omicron infection, mirroring data from the United States and South Africa. However, it remains vitally important that all febrile infants are assessed by a trained clinician to consider other causes of fever.

Note:
Funding: None to declare.

Declaration of Interests: None to declare.

Ethics Approval Statement: No ethical approval needed. The UKHSA has legal permission under Regulation 3 of The Health Service (Control of Patient Information) Regulations 2002, to conduct national surveillance of communicable diseases in England and, as such, individual patient consent is not required.

Keywords: SARS-CoV-2, Omicron, COVID-19, Children, Infant, Paediatrics

JEL Classification: i1