SARS, MERS, nSARS-CoV-2 infections and diseases: Emerging threats to public health

ABSTRACT

Since the outbreak of the novel SARS-CoV-2, i.e., in December 2019, in Wuhan, China, more than 110 million cases have been reported, with 2.5 million deaths worldwide. It is not the first time, earlier in 2002–2003 SARS-CoV and in 2010 MERS-CoV outbreaks were reported. However, in 2019 novel SARS-CoV-2 outbreak prevailed to a great extent worldwide. Still, we are in the middle of a pandemic and seek effective vaccines and therapeutics for prevention and complete cure, respectively. There are new strains of novel SARS-CoV2 reported in a different part of the world. Considering the research data and statistics from CDC and WHO, the novel SARS-CoV-2 is the second most deadly viral outbreak after the Spanish Flu in 1918. Compared to previous coronavirus outbreak cases, the novel SARS-CoV-2 attack was reported to be more transmissible but less fatal. Among the top five countries worst affected by novel SARS-CoV-2 infection and mortality are the United States, India, Brazil, Russia, and the United Kingdom. Similarly, many countries in Europe, including Spain and Italy have endured a similar impact with viral outbreaks. The pandemic started in China and traveled to Europe, the United States and the American continent, and many Asian countries, including Russia and India, which are “hot spots” for virus infection and disease outbreak. In the first wave of the virus outbreak, many countries including China, South Korea, Japan, New Zealand, etc., successfully controlled and contained the virus, using strict social distancing and other containment measures. The reproductive number (R 0) and fatality rate of COVID-19 disease caused by novel SARS-CoV-2 infection vary among different populations. However, infection and disease are a function of several risk factors, including age, sex, comorbidity, and strain of novel SARS-CoV-2. Simultaneously, there is a massive effort in research for diagnostic, therapeutic, and vaccine development. It was the first time in human history where a clinical diagnosis was implemented very early in the case of a pandemic. Several antiviral drugs, antiinflammatory agents, immune modulators, and vitamins were used to control the COVID-19 disease. © 2022 Elsevier Inc. All rights reserved.