Clinical manifestations of COVID-19: An overview of 102 systematic reviews with evidence mapping

OBJECTIVE Coronavirus disease 2019 (COVID-19) has rapidly spread worldwide, but there is so far no comprehensive analysis of all known symptoms of the disease. Our study aimed to present a comprehensive picture of the clinical symptoms of COVID-19 using an evidence map. METHODS We systematically searched MEDLINE via PubMed, Web of Science, Embase, and Cochrane library from their inception to March 16, 2021. We included systematic reviews reporting the clinical manifestations of COVID-19 patients. We followed the PRISMA guidelines, and the study selection, data extraction, and quality assessment were done by two individuals independently. We assessed the methodological quality of the studies using AMSTAR. We visually presented the clinical symptoms of COVID-19 and their prevalence. RESULTS A total of 102 systematic reviews were included, of which, 68 studies (66.7%) were of high quality, 19 studies (18.6%) of medium quality, and 15 studies (14.7%) of low quality. We identified a total of 74 symptoms including 17 symptoms of the respiratory system, 21 symptoms of the neurological system, 10 symptoms of the gastrointestinal system, 16 cutaneous symptoms, and 10 ocular symptoms. The most common symptoms were fever (67 studies, ranging 16.3%-91.0%, pooled prevalence: 64.6%, 95%CI, 61.3%-67.9%), cough (68 studies, ranging 30.0%-72.2%, pooled prevalence: 53.6%, 95%CI, 52.1%-55.1%), muscle soreness (56 studies, ranging 3.0%-44.0%, pooled prevalence: 18.7%, 95%CI, 16.3%-21.3%), and fatigue (52 studies, ranging 3.3%-58.5%, pooled prevalence: 29.4%, 95%CI, 27.5%-31.3%). The prevalence estimates for COVID-19 symptoms were generally lower in neonates, children and adolescents, and pregnant women than in the general populations. CONCLUSION At least 74 different clinical manifestations are associated with COVID-19. Fever, cough, muscle soreness, and fatigue are the most common, but attention should also be paid to the rare symptoms that can help in the early diagnosis of the disease.