Study and overview of the novel corona virus disease (COVID-19)

In December 2019, a new disease with pneumonia-like symptoms was spreading throughout Wuhan in China which was entitled as novel coronavirus disease or COVID -19 caused by the virus SARS CoV-2. Within a span of a few days, this disease became a global threat and was termed as a pandemic by the World Health Organization (WHO) on March 11, 2020, since then the disease has affected more than 1.5 crore people worldwide and around 6.9 lakh people in India as of July 5, 2020. The origin of the COVID-19 disease has been traced back to the bats, but the intermediary contact is unknown. The disease spreads by respiratory droplets and contaminated surfaces. In most cases, the virus shows mild symptoms like fever, fatigue, dyspnea, cough, etc. which may become severe if appropriate precautions are not adhered to. For people with comorbidities (usually elderly) the disease may turn deadly and cause pneumonia, Acute Respiratory Disease Syndrome (ARDS), and multi-organ failure, thereby affecting a person's ability to breathe leading to being put on the ventilator support. The reproduction number (Rℴ) of COVID-19 is much higher than its predecessors and genetically similar diseases like SARS-CoV and MERS-CoV. This paper discusses the epidemiological characteristics of the SARS-CoV-2 virus, its phylogenetic relationship with the previous pandemic causing viruses such as SARS-CoV-1 and MERS-CoV and analyzes the various responses to this global pandemic worldwide, focusing on the actions taken by India and their outcomes.