Persistence of Anti-SARS-CoV-2 Antibodies Six Months After Infection in an Outbreak With Five Hundred COVID-19 Cases in Borriana (Spain): A Prospective Cohort Study (preprint)

In March 2020, several mass gathering events were related to the Falles festival in Borriana (Spain), resulting in a 536 laboratory-confirmed COVID-19 cases outbreak among participants. Our objective was to estimate anti-SARS-CoV-2 antibodies persistence six months after and factors associated with antibody response. A prospective population-based cohort study was carried out by the Public Health Center of Castellon and the Emergency and Clinical Analysis and Microbiology Services of Hospital de la Plana in Vila-real. In October 2020, sero-epidemiologic study to estimate the persistence of anti-SARS-CoV-2 antibodies by a electrochemiluminescence immunoassay (ECLIA) was implemented. We enrolled 484 (90.2%) of the 536 members of the initial outbreak cohort and detected persistent antibodies in 479 (99%) without re-infection episodes. Five participants had a negative antibody test. Factors associated with a negative result were a lower body mass index (BMI), and less contact with other COVID-19 cases. Among the 469 participants with two ECLIA tests, 96 (20.5%) had an increase of antibodies and 373 (79.5%) a decline. Increased antibodies were associated with older age, higher BMI, more severe illness, and low current smokers. After a COVID-19 infection, a high proportion of cases maintained detectable anti-SARS-CoV-2 antibodies.

The Spectrum of COVID-19 in Children in Spain (preprint)

Background: We aimed to identify the spectrum of disease in children with COVID-19, and the risk factors for admission in paediatric intensive care units (PICUs). Methods: : We conducted a multicentre, prospective study of children with SARS-CoV-2 infection in 76 Spanish hospitals. We included children with COVID-19 or multi-inflammatory syndrome (MIS-C) younger than 18 years old, attended during the first year of the pandemic. Results: We enrolled 1 200 children. A total of 666 (55.5%) were hospitalized, and 123 (18.4%) required admission to PICU. Most frequent major clinical syndromes in the cohort were: mild syndrome (including upper respiratory tract infection and flu-like syndrome, skin or mucosae problems and asymptomatic), 44.8%; bronchopulmonary syndrome (including pneumonia, bronchitis and asthma flare), 18.5%; fever without a source, 16.2%; MIS-C, 10.6%; and gastrointestinal syndrome, 10%. In hospitalized children, the proportions were: 28.5%, 25.7%, 16.5%, 19.1% and 10.2%, respectively. Risk factors associated with PICU admission were MIS-C (odds ratio [OR]: 37.5,95% CI 22.7 to 57.8), moderate or severe liver disease (OR: 9,95% CI 1.6 to 47.6), chronic cardiac disease (OR: 4.8,95% CI 1.8 to 13) and asthma or recurrent wheezing (OR: 2.8,95% CI 1.3 to 5.8). However, asthmatic children were admitted into the PICU due to MIS-C or pneumonia, not due to asthma flare. Conclusion: Hospitalized children with COVID-19 usually present as one of five major clinical phenotypes of decreasing severity. Risk factors for PICU include MIS-C, elevation of inflammation biomarkers, asthma, moderate or severe liver disease and cardiac disease.