Title: Clinical spectrum of coronavirus disease 2019 in Iceland: population based cohort study
Author: Elias Eythorsson, Dadi Helgason, Ragnar Freyr Ingvarsson, Helgi K Bjornsson, Lovisa Bjork Olafsdottir, Valgerdur Bjarnadottir, Hrafnhildur Linnet Runolfsdottir, Solveig Bjarnadottir, Arnar Snaer Agustsson, Kristin Oskarsdottir, Hrafn Hliddal Thorvaldsson, Gudrun Kristjansdottir, Brynja Armannsdottir, Agnar Bjarnason, Birgir Johannsson, Olafur Gudlaugsson, Magnus Gottfredsson, Martin I Sigurdsson, Olafur S Indridason, Runolfur Palsson
Objective To characterise the symptoms of coronavirus disease 2019 (covid-19).
Design Population based cohort study.
Participants All individuals who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by reverse transcription polymerase chain reaction (RT-PCR) between 17 March and 30 April 2020. Cases were identified by three testing strategies: targeted testing guided by clinical suspicion, open invitation population screening based on self referral, and random population screening. All identified cases were enrolled in a telehealth monitoring service, and symptoms were systematically monitored from diagnosis to recovery.
Main outcome measures Occurrence of one or more of 19 predefined symptoms during follow-up.
Results Among 1564 people positive for SARS-CoV-2, the most common presenting symptoms were myalgia (55%), headache (51%), and non-productive cough (49%). At the time of diagnosis, 83 (5.3%) individuals reported no symptoms, of whom 49 (59%) remained asymptomatic during follow-up. At diagnosis, 216 (14%) and 349 (22%) people did not meet the case definition of the Centers for Disease Control and Prevention and the World Health Organization, respectively. Most (67%) of the SARS-CoV-2-positive patients had mild symptoms throughout the course of their disease.
Conclusion In the setting of broad access to RT-PCR testing, most SARS-CoV-2-positive people were found to have mild symptoms. Fever and dyspnoea were less common than previously reported. A substantial proportion of SARS-CoV-2-positive people did not meet recommended case definitions at the time of diagnosis.