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

Abstract

Description 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.