An update on SARS-CoV-2/COVID-19 with particular reference to its clinical pathology, pathogenesis, immunopathology...

Coronavirus Disease 2019 (COVID-19), emerged in early December 2019 in China and became a pandemic situation worldwide by its rapid spread to more than 200 countries or territories. Bats are considered as the reservoir host, and the search of a probable intermediate host is still going on. The severe form of the infection is associated with death is mainly reported in older and immune-compromised patients with pre-existing disease history. Death in severe cases is attributed to respiratory failure associated with hyperinflammation. Cytokine storm syndrome associated with inflammation in response to SARS-CoV-2 infection is considered as the leading cause of mortality in COVID-19 patients. COVID-19 patients have thus higher levels of many proinflammatory cytokines and chemokines. The blood laboratory profile of the COVID-19 patients exhibits lymphopenia, leukopenia, thrombocytopenia, and RNAaemia, along with increased levels of aspartate aminotransferase. SARS-CoV-2 infection in pregnant women does not lead to fetus mortality, unlike other zoonotic coronaviruses such as SARS-CoV and MERS-CoV, and there is, to date, no evidence of intrauterine transmission to neonates. Rapid diagnostics have been developed, and significant efforts are being made to develop effective vaccines and therapeutics. In the absence of any virus-specific therapy, internationally, health care authorities are recommending the adoption of effective community mitigation measures to counter and contain this pandemic virus. This paper is an overview of this virus and the disease with a particular focus on SARS-CoV-2/COVID-19 clinical pathology, pathogenesis, and immunopathology, along with recent research developments.