Individuals With SARS-CoV-2 Infection During the First and Second Waves in Catalonia, Spain: Retrospective Observational Study Using Daily Updated Data

Coronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Epidemiologia; ComparacióCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Epidemiología; ComparaciónCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Epidemiology; ComparisonA description of individuals with SARS-CoV-2 infection comparing the first and second waves could help adapt health services to manage this highly transmissible infection.Objective: We aimed to describe the epidemiology of individuals with suspected SARS-CoV-2 infection, and the characteristics of patients with a positive test comparing the first and second waves in Catalonia, Spain. Methods: This study had 2 stages. First, we analyzed daily updated data on SARS-CoV-2 infection in individuals from Girona (Catalonia). Second, we compared 2 retrospective cohorts of patients with a positive reverse-transcription polymerase chain reaction or rapid antigen test for SARS-CoV-2. The severity of patients with a positive test was defined by their admission to hospital, admission to intermediate respiratory care, admission to the intensive care unit, or death. The first wave was from March 1, 2020, to June 24, 2020, and the second wave was from June 25, 2020, to December 8, 2020.Results: The numbers of tests and cases were lower in the first wave than in the second wave (26,096 tests and 3140 cases in the first wave versus 140,332 tests and 11,800 cases in the second wave), but the percentage of positive results was higher in the first wave than in the second wave (12.0% versus 8.4%). Among individuals with a positive diagnostic test, 818 needed hospitalization in the first wave and 680 in the second; however, the percentage of hospitalized individuals was higher in the first wave than in the second wave (26.1% versus 5.8%). The group that was not admitted to hospital included older people and those with a higher percentage of comorbidities in the first wave, whereas the characteristics of the groups admitted to hospital were more alike.This work was supported by grants from the European Union ERDF funds (Network for Prevention and Health Promotion in Primary Care, RedIAPP–CARDIOCAT; RD16/0007/0004) and from the Agency for Management of University and Research Grants (AGAUR; 2017-SGR 1146). We thank Eric Tornabell for his technical support. We also thank all health care professionals for their ceaseless work to care for COVID-19 patients in this pandemic

Persons with SARS-CoV-2 during the First and Second Waves in Catalonia (Spain): A Retrospective Observational Study Using Daily Updated Data

Coronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Epidemiologia; CronologiaCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Epidemiología; CronologíaCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Epidemiology; TimelineDescription of persons with infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) comparing the first and second waves could help adapt the health services to manage this highly transmissible disease. We aimed to describe the epidemiology of persons with suspected SARS-CoV-2 infection, and the characteristics of patients with a positive test comparing first and second waves in Catalonia, Spain. This study had two stages. First, we analysed daily updated data on SARS-CoV-2 infection of persons from Girona (Catalonia); second, we compared two retrospective cohorts of patients with a positive reverse-transcription polymerase chain reaction or rapid antigenic test for SARS-CoV-2. Severity of patients with a positive test was defined by their admission to hospital; intermediate respiratory care; intensive care; or by decease. The first wave was from 01/03/2020 to 24/06/2020, and the second from 25/06/2020 to 08/12/2020.A higher percentage of persons with a positive test for SARS-CoV-2 infection was found in the first wave, despite being a less numerous group, likely due to improvement in the surveillance systems during the second wave. The characteristics of persons with the infection in the first and second waves differed substantially; persons in the first wave were older and in worse health condition