key: cord-0896971-z3t5kco9 authors: Mann, Jennifer A; Bird, Paul W; Bandi, Srini; Tang, Julian W title: Asymptomatic SARS-CoV-2-infected children attending hospital with non-COVID-19 diagnoses, March 2020-February 2021 date: 2021-05-13 journal: J Infect DOI: 10.1016/j.jinf.2021.05.002 sha: 09378f6d92fe70fec7f5b4fa4f413cfde88e8c95 doc_id: 896971 cord_uid: z3t5kco9 nan About 20-30% of children infected with SARS-CoV-2 are asymptomatic and may present to hospital for other medical reasons We performed a 1-year retrospective surveillance audit to determine the incidence of such paediatric cases in our hospital Of 1427 admissions, 80 (5.61%) were SARS-infected of which 52 (65%) had COVID-19 symptoms and 16 (20%) were asymptomatic. Asymptomatic children may be detected by a universal screening policy that tests all hospital admissions for SARS-CoV-2 Without a hospital-wide screening policy, such children may present an undiagnosed infection risk to staff and other patients Asymptomatic SARS-CoV-2-infected children attending hospital with non-COVID- 19 This may become a seasonal problem, as we have seen with other respiratory viruses, such as respiratory syncytial virus (RSV) [3] and influenza [4] . Indeed, children with asymptomatic SARS-CoV-2 infection can show higher nasopharyngeal viral loads than hospitalised adults with severe disease [5] , and can shed virus for up to 3 weeks [2] . Throughout the COVID-19 pandemic in the UK during 2020, asymptomatic SARS-CoV-2 infections in children were difficult to assess directly, as only symptomatic children were tested during the first wave of the pandemic, and only if they required hospitalisation. Most community SARS-CoV-2 testing was stopped after 12 March 2020 [6] for both adults and children. From June 2020, UK national guidance mandated that all new hospital admissions undergo screening for COVID-19 [7] . This universal screening policy allowed us to monitor SARS-CoV-2 infection rates in children who were both symptomatically and asymptomatically infected with SARS-CoV-2, with some of the latter group being admitted for other medical problems. Our Children's Hospital serves a pediatric population of 233,796 throughout Leicester, Leicestershire and Rutland [8] , seeing over 60,000 children in the children's Emergency Department (ED), annually. We performed a 1-year retrospective surveillance audit to determine the incidence of asymptomatic paediatric SARS-CoV-2 infections admissions. Inclusion criteria: all under-18-year olds who had been seen and swabbed An 'unclear' COVID-19 status was assigned when a patient presented with at least one COVID-19-compatible symptom but who also had a concurrent illness with overlapping symptom patterns, e.g. a child admitted with fever and abdominal pain, who had surgically proven appendicitis, but who was also found to be SARS-CoV-2 positive. Out of a total of 11,793 nasopharyngeal swabs, 202 (1.71%) were SARS-CoV-2 PCR positive. Of these, swabs from 80 patients met our inclusion criteria for laboratoryconfirmed SARS-CoV-2 infection. Of these 80 cases, 68 were swabbed in ED (85%) and 11 (13.75%) by their destination inpatient ward and 1 (1.25%) by the mortuary following an out-of-hospital cardiac arrest admitted via ED. 2021 [2] . Of the 52 children displaying COVID-19 symptoms; 23/52 (44.23%) had fever only, 13/52 (25%) had fever and a respiratory symptom, 11/52 (21.15%) had respiratory symptoms only, 2/52 (3.85%) presented with febrile seizures, 2/52 (3.85%) with headaches alone and 1/52 (1.92%) with skin discoloration of their extremities. Stratifying by school stage, the symptomatic and asymptomatic infections were, respectively: preschool: 38/80 (47.5%), 8/80 (10%); primary school: 2/80 (2.5%), 2/80 (2.5%); secondary school: 12/80 (15%), 6/80 (7.5%). The overall percentage of new paediatric admissions with asymptomatic SARS-CoV-2 infection remained at or below 1.04%, until September 2020 when it rose to 2.04%, then further increased to 2.14% in November 2020. In addition, whilst schools remained open throughout the 2020 autumn term, it was noticeable that dips in asymptomatic SARS-CoV-2 case numbers occurred in October 2020 (0.80%) and December 2020 (0.56%), which coincided with the school half-term and Christmas holidays (Figure 1 ). This may have been due to an overall reduction in social contacts between children during these school breaks. Asymptomatic SARS-CoV-2 infections presenting to hospital for other, non-COVID-19-related medical reasons may pose a nosocomial transmission risk to other patients and staff, as has been seen with other seasonal respiratory viruses [3, 4] . Even where bedside rapid diagnostic tests are available, these can still take 30-60 minutes to complete, and patient waiting areas can still allow some degree of close-contact mixing, particularly with active young children. This risk may increase during school term times, as the percentage of asymptomatic paediatric SARS-CoV-2 infections being seen in hospital rises. We therefore urge paediatric ED and outpatient teams to be particularly vigilant for potentially asymptomatic SARS-CoV-2-infected children during school terms, particularly as SARS-CoV-2/COVID-19 becomes more endemic and seasonal, and whilst children are still not eligible COVID-19 vaccinations. Gastrointestinal manifestations are associated with severe pediatric COVID-19: a study in tertiary hospital Clinical Characteristics and Viral RNA Detection in Children With Coronavirus Disease 2019 in the Republic of Korea Respiratory syncytial virus evaluation among asymptomatic and symptomatic subjects in a university hospital in Sao Paulo, Brazil, in the period of 2009-2013. 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