Coronavirus: A Brief Overview

The coronavirus, which was first discovered in December 2019 in Wuhan, China, has transformed the world, including the United States [1]. Americans now face a reality that includes widespread panic, empty streets and sidewalks, locked businesses, travel bans, government-issued shelter-in-place orders, above-capacity hospitals, and thousands of infections and deaths, all from a mysterious respiratory virus [1]. Just a few months ago, this combination of events would have seemed to be the storyline of an apocalyptic film, but it is now an everyday reality.


How does the disease spread?

According to the Centers for Disease Control and Prevention, COVID-19 is a disease that is spread primarily through respiratory droplets [2]. The virus is more specifically known as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), and is a single-stranded RNA virus of the genus Betacoronavirus [3].


Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and Middle East Respiratory Syndrome Coronavirus (MERS-CoV) are previous strains of Coronavirus. One genetic sequencing analysis found that SARS-CoV-2 is approximately 89% similar to SARS-like (SL) Coronaviruses originating from bats, while it is about 79% similar to SARS-CoV and only about 50% similar to MERS-CoV. [3]


Based on sequencing and analysis of SARS-CoV-2 genes from cases in Wuhan, China, the likely transmission of the novel Coronavirus was animal to human. According to this study, the first case may have been caused by bats or bat feces that polluted the markets or the part of Wuhan, China where the outbreak first began [3]. However, a more recent analysis of the SARS- CoV 2 genome found that a spike protein coded for in the SARS-COV-2 genome is 91% analogous to a comparable protein sequence found in the lungs of sick pangolins, a scaly animal similar in appearance to an anteater. The pangolin genome sequence study states that “the receptor binding domain of the spike protein from the pangolin coronavirus had only five amino acid differences from SARS-CoV-2, compared with 19 differences between the human and bat viral proteins.” Researchers claim that the nearly identical nature of the proteins indicate that pangolins are the most likely the intermediary hosts between bats and humans, but other hosts remain plausible [4].” This indicates that pangolins may have been a vector for the transmission of the disease from bats to humans.


How fast is it growing?

Early studies of the January 2020 COVID-19 Mainland China revealed that new COVID-19 cases followed a pattern of exponential growth [3]. The mean reproductive number, known as R0, based on these early Mainland China SARS-CoV-2 cases, was found to be approximately 3.0 [2]. R0, pronounced R naught, is a statistical term that describes how contagious an infection is. An R0 of 1.0, for example, indicates that each infected person transmits the virus to on average one other person. A R0 value greater than 1.0 indicates that the infectious disease will spread and can cause an outbreak or epidemic. The R0 value needs to be brought to less than one to control an outbreak, but this can be challenging because of “super spreading,” which occurs when one person transmits the virus to tens or hundreds of people, such as at a large gathering like a funeral or religious service [5].


The R0 ranges for comparative viral infectious diseases include: Ebola, 2014 [1.51 to 2.53], H1N1 Influenza, 2009 [1.46 to 1.48], Seasonal Influenza [0.9 to 2.1], Measles, [12 to 18], MERS [~1], Polio [5 to 7], SARS Pandemic [<1 to 2.75], and Smallpox [5 to 7]. The accuracy of the estimated R0 value for SARS-CoV-2 remains uncertain due to the possibility of a large number of missed cases and lack of a complete understanding of SARS-CoV-2 and its infectivity [6].


The incubation period and doubling time of the virus were both found to be 6.4 days. It is also probable that a portion of the spread of the novel Coronavirus resulted from infected, but asymptomatic individuals who transmitted the virus to others [3].


What are the symptoms?

The most common clinical signs of infection are fever (92.8%), cough (69.8 %) and shortness of breath (34.5%). Nasal discharge (4.0%) and sore throat (5.1%) were less commonly found. The outcomes of the infection are varied and can include ICU stays, ventilator requirement, shock, acute respiratory distress syndrome, acute renal injury and death [3].


How can it be prevented?

According to the World Health Organization (WHO), the best way to prevent COVID-19 is to consistently maintain clean hands by using an alcohol- based liquid or gel or washing hands with soap and water. The World Health Organization also suggests “social distancing,” which is the practice of keeping distance between yourself and others, especially from persons that are coughing or sneezing. The WHO also suggests avoiding touching your eyes, nose and mouth, coughing and sneezing into a tissue or bent elbow to prevent the spread of droplets and staying home if you feel ill. If you develop severe illness, which includes fever, coughing and shortness of breath, then the WHO suggests that you contact your medical provider [7].


What are the societal impacts of this pandemic?

Along with being one of those most devastating Public Health crises in our lifetimes, this pandemic has also altered personal lives. Social distancing has kept most Americans home for weeks and has the potential to continue for several more weeks to months. Even when it is safe to have contact with others again, there could be a lasting impact of these new social norms — people may begin to avoid personal interactions more often, including shaking hands, in-person meetings, and even collective religious worship. Experiencing this pandemic may also lead to more Americans questioning the hyperindividualism that was so prevalent in the US before, since it is now clear that our lives are more connected than we might have previously thought. This realization could have many societal impacts, including further investment in public goods and services, reform of the US healthcare system, a shift to holding more services over the internet, increased use of telemedicine, and political and community support for a public funding of child and elderly care [8]. In short, the world we will return to when self-quarantine and social distancing ends may not be the same world we left.

References:

  1. Rabin, R. C. (2020, January 21). First Patient With Wuhan Coronavirus Is Identified in the U.S. Retrieved March 28, 2020, from https://www.nytimes.com/2020/01/21/health/cdc-coronavirus.html

  2. How Coronavirus Spreads. (2020, March 4). Retrieved March 28, 2020, from https://www.cdc.gov/coronavirus/2019-ncov/prepare/transmission.html

  3. Lai, C. C., Shih, T. P., Ko, W. C., Tang, H. J., & Hsueh, P. R. (2020). Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and coronavirus disease-2019 (COVID-19): The epidemic and the challenges. International Journal of Antimicrobial Agents, 55(3), 105924. Doi: 10.1016/j.ijantimicag.2020.105924.

  4. Missing link in coronavirus jump from bats to humans could be pangolins, not snakes. (2020, March 26). Retrieved March 29, 2020, from https://www.sciencedaily.com/releases/2020/03/200326144342.htm

  5. Ramirez, V. B. (2016, August 10). What Is R0?: Gauging Contagious Infections. Retrieved 29, 2020, from https://www.healthline.com/health/r-nought-reproduction-number#rsubsubvalues

  6. Eisenberg, J. (2020, February 12). R0: How Scientists Quantify the Intensity of an Outbreak Like Coronavirus and Its Pandemic Potential: The Pursuit: University of Michigan School of Public Health: Coronavirus: Pandemic. Retrieved March 29, 2020, from https://sph.umich.edu/pursuit/2020posts/how-scientists-quantify-outbreaks.html

  7. World Health Organization . (2020 18). Coronavirus Disease (COVID-19) Advice For Public. Retrieved 29, 2020, from https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public

  8. Grunwald, M. (2020, March 19). Coronavirus Will Change the World Permanently. Here’s How. Retrieved 29, 2020, from https://www.politico.com/news/magazine/2020/03/19/coronavirus-effect-economy-life-society-analysis-covid-135579

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