Comprehensive review of coronavirus disease 2019 (COVID-19)

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first identified in December 2019 in Wuhan, the capital of China's Hubei province and has rapidly spread all over the world. The World Health Organization (WHO) declared the outbreak to be a Public Health Emergency of International Concern on 01/30/2020 and recognized it as a pandemic on 03/11/2020. The number of people diagnosed with COVID-19 worldwide crossed the one million mark on 04/02/2020; two million mark on 04/15/2020; three million mark on 04/27/2020 and the four million mark on 05/09/2020. Despite containment efforts, more than 187 countries have been affected with more than 4,178,346 cases in the world with maximum being in USA (1,347,936) followed by 227,436 in Spain and 224,422 in United Kingdom as of May, 2020. COVID-19 is the latest threat to face mankind cutting across geographical barriers in a rapidly changing landscape. This review provides an update on a rapidly evolving global pandemic. As we face the threat of emerging and re-emerging infectious diseases, this is a stark reminder to invest in population health, climate change countermeasures, a global health surveillance system and effective research into identifying pathogens, their treatment and prevention and effective health delivery systems.