Coronavirus Disease 2019 Symptoms on First Wave and Second Wave: An Overview

Abstract

During this decade, a fast spreading threat coronavirus has to infect human populations. This virus was first identified in Wuhan, China, in humans exposed to a seafood market. The virus is officially called 2019-novel coronavirus. The studies conducted during its initial outbreak show that human-to-human transmission was limited or non-existent, but it was not a correct assumption. Recently, the virus is reported in almost all the countries and territories. It is the third epidemic caused by coronavirus in the 21st century, already surpassing severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) in the number of individuals infected. The World Health Organization (WHO) reported that as of 6:19 pm CEST, June 11, 2021, there have been more than 174 million confirmed cases of coronavirus disease 2019 (COVID-19), including more than 3 million deaths, reported to the WHO. Many research works have been published and actively conducting on the threatening spread of the virus. The main symptoms of COVID‐19 included fever, fatigue, and cough, which are similar to that of SARS‐CoV- and MERS‐CoV-infected cases. Much literature reported various symptoms of COVID‐19, but the comprehensive review is few. The purpose of the paper is primarily to review the symptoms of different waves of COVID-19 infection. Awareness of the COVID-19 symptoms may help in early diagnosis, to control virus spread, and risk stratification.