April 28th, 2020

Dear reader:

During this time of trial, there has been a lot of misinformation and fear in our lives. At times it is challenging to be able to determine what is true.  How severe is this novel coronavirus, and how does it compare to other viruses of its type? What sources can we even trust? Often the scientific studies and articles created use vocabulary that is too advanced for the average reader. The use of complex language makes it even harder to find accurate, comprehensible information. In order to combat the misinformation running rampant and create an accurate representation and viewpoint of the virus, I have summarized information on COVID-19 and SARS.

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To begin with, we must cover the basics. What is a coronavirus? Coronaviruses are a family of viruses with the scientific name Coronaviridae [4]. The genera of this kind of virus that affect mammals are that of Alphacoronavirus, Betacoronavirus, and  Deltacoronavirus [4].  SARS is considered a Betacoronavirus [4]. Coronaviruses are named after the Latin word for a crown – corona – as a reference to its crown-like structure, which I will get to later [4]. The full name for the novel coronavirus is COVID-19, which stands for Coronavirus Disease 19 – the 19 refers to its emergence in the year 2019 [3]. The full name for SARS is SARS-CoV, which stands for Severe Acute Respiratory Syndrome Coronavirus [1+2].

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SARS originated in the Guangdong province of China in November of 2002 from a suspected animal reservoir such as bats (sound familiar?) [2]. It then proceeded to spread to around 26 countries, including Canada, causing around 8000 cases and about 774 deaths [1+2]. Since the 2002-2003 outbreak, there have been some small outbreaks, but the virus has not appeared since 2004 [1+2]. COVID-19 has a similar background to SARS. It was first reported to the World Health Organization (WHO) on December 31st, 2019, in the city of Wuhan, China [5]. Within four months, it had spread across the globe and was officially declared a pandemic on March 11th, 2020 [3+5]. As of Aril 25th, 2020, there were 2 810 325 confirmed cases, and 193 825 confirmed deaths from the novel virus [3+5+6]. As is the case with most coronaviruses, COVID-19 and SARS both spread through close person-to-person contact – usually through exposure to droplets of saliva, stool, or other excretions that contain the virus [1+2+3].

The symptoms exhibited by people with these viruses are usually very similar to that of other coronaviruses, the common cold, and other influenza-like illnesses [1+2+3]. Due to the reality that there are no symptoms unique to SARS and COVID-19, the only guaranteed way to diagnose someone with these illnesses is through testing [1+2+3]. The symptoms of SARS can include myalgia, shivering, high fever, diarrhea, dry coughing, pneumonia, malaise, headache, and other influenza-like symptoms [1+2]. COVID-19 include dry cough, fever, lack of energy, shortness of breath, aches and pains, sore throat [3]. Some patients will experience diarrhea, nausea, or a runny nose [3]. Patients with SARS are only contagious after exhibiting symptoms (usually in the second week of illness), while patients with COVID-19 can be contagious before first exhibiting symptoms [1+2+3].

The structure of coronaviruses is suited explicitly to attacking pulmonary cells [4]. They are made up of RNA (Ribonucleic Acid – it is genetic material) strands packed inside of a membranous envelope that is formed by a nucleocapsid protein that makes up a helical capsid that is then surrounded by the envelope made up of membrane proteins, envelope proteins, and spike proteins [4]. The spike proteins embedded withing the envelope give the virus the appearance of having a crown – hence the name coronavirus [4].

                           

Both COVID-19 and SARS affect the lungs predominantly and are combatted by the immune system-related components of the blood, such as various types of white blood cells [1+2+3]. Usually, the viruses enter the body through the eyes, mouth, or other mucous membranes [1+2+3]. The spike proteins on SARS coronaviruses bind to receptors embedded in the lung cell membranes [4]. Binding to receptors then allows the virus to enter the cell through endocytosis [4]. It then multiplies within the cells and kills it, using its primary antigen, such as the 46-kDa nucleoprotein, releasing more of the virus [4+7]. The reason that COVID-19 can cause a patient’s condition to decline drastically is through bringing on something called a cytokine storm [11]. A cytokine storm is when the cytokine cells (molecules that help coordinate the immune response to a virus) call for an excessive ‘summoning’ of immune cells that end up not only attacking the virus, but also the healthy cells [11]. This increase in immune cells can lead to even more cell necrosis (death) than would happen otherwise [11]. Once people have contracted the viruses, they build up antibodies that prevent them from contracting the virus again [7]. That means that they are immune to the virus [7].

So now that we know about how these viruses work, how dangerous are they? Who is most vulnerable? Which virus is more deadly, SARS, or COVID-19?

Something essential to specify is that anyone can contract SARS or COVID-19 [1+2+3]. Those who are most susceptible to contracting severe cases of SARS and COVID-19 are those who are elderly, immunosuppressed, and immunocompromised [2]. Most deaths from SARS occurred in the elderly and immunocompromised [9]. However, health workers are also susceptible to contracting viruses [9]. During the SARS outbreak of 2002-2003, health workers accounted for 21% of cases [9]. In Canada, the death rate from SARS in individuals over 60 was 83%, while the median age of SARS deaths was 75 years [9]. In one study, around 21% of SARS patients were admitted into the intensive care unit, and 13% required ventilator support [8]. The death rate can range from 0% to over 50% depending on the age group affected, but the estimated average is around 15% [9]. In regards to COVID-19, because this virus is still entirely novel, there is very little information and statistics regarding its death rate. As of March 3rd, 2020, the global mortality rate from COVID-19 was 3.4% of confirmed cases [10]. These percentages mean that the death rate from COVID-19 is about 11.6% lower than that of SARS.

 

There are currently no vaccines, cures, or treatments to combat SARS or COVID-19 [1+2+3]. However, some experimental vaccines are in development [2+3+5]. The treatments being used are focused on alleviating the symptoms [2+3]. While there is currently no infallible way to prevent getting the virus, the WHO has released preventative measures to take care of oneself and others [2]. These include: Following travel and prevention advice issued by the WHO, following respiratory etiquette (covering mouth when coughing or sneezing), washing hands regularly or disinfecting with an antiseptic alcohol rub (hand sanitizer), practicing physical distancing from people coughing or sneezing, staying home if you feel unwell, avoiding touching face or other mucous membranes, and refraining from smoking, vaping, or other activities that weaken the lungs [2+3].

 

In conclusion, both SARS and COVID-19 are similar viruses from the family Coronaviridae [4]. They mainly affect the respiratory system, and while both can cause severe and possibly fatal infection in some, SARS is more severe than COVID-19, where most cases are usually mild [1+2+3]. It is essential to acknowledge, though, that there is limited information available for either of these viruses, because one is very new, while the other has not seen a reported case in around 16 years, so some of the information provided here may not be relevant or accurate even by the end of 2020 [2]. This lack of information is why it is so crucial that we actively remain engaged in learning and independently creating our own opinions. Knowledge is indeed power, but not everything presented as knowledge is accurate and correct. I encourage you to take the time to review the sources I have cited (and others) to further inform and educate yourself on these topics.

Have a wonderful day, and stay safe.

Sincerely, a well-meaning student,

Danica

 

PS. My resources:

1. Centers for Disease Control and Prevention “SARS Basics Fact Sheet” Internet: https://www.cdc.gov/sars/about/fs-sars.html Last Modified: 2017-12-6 (2020-04-25)

2. World Health Organization “SARS (Severe Acute Respiratory Syndrome)” Internet: https://www.who.int/ith/diseases/sars/en/ Last Modified: Unspecified (2020-04-25)

3. World Health Organization “Coronavirus” Internet: https://www.who.int/health-topics/coronavirus#tab=tab_1 Last Modified: 2020 (2020-04-25)

4. Fang Li “Structure, Function, and Evolution of Coronavirus Spike Proteins” Internet: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5457962/  Last Modified: 2016-09-29 (2020-04-26)

5. World Health Organization “Rolling updates on Coronavirus Disease (COVID-19)” Internet: https://www.who.int/emergencies/diseases/novel-coronavirus-2019/events-as-they-happen Last Modified: 2020-04-24 (2020-04-26)

6. World Health Organization “Coronavirus disease (COVID-19) Pandemic” Internet: https://www.who.int/emergencies/diseases/novel-coronavirus-2019 Last Modified: 2020-04-26 (2020-04-26)

7. JSTOR, Xinchun Chen, Boping Zhou, Meizhong Li, Xiaorong Liang, Huosheng Wang, Guilin Yang, Hui Wang and Xiaohua Le (2004-04-01)“The Journal of Infectious Diseases” Vol. 189, No. 7, pp. 1158-1163 Available: www.jstor.org/stable/30075921  (2020-04-25)

8. Ping Tim Tsui, Man Leung Kwok, Hon Yuen, and Sik To Lai “Severe Acute Respiratory Syndrome: Clinical Outcome and Prognostic Correlates” Internet:  https://wwwnc.cdc.gov/eid/article/9/9/03-0362_article Last Modified: 2011-01-03 (2020-04-27)

9. World Health Organization “Consensus document on the epidemiology of severe acute respiratory syndrome (SARS)” Internet: https://www.who.int/csr/sars/en/WHOconsensus.pdf Last Modified: 2003 (2020-04-27)

10. Worldometer “Coronavirus (COVID-19) Mortality Rate” Internet: https://www.worldometers.info/coronavirus/coronavirus-death-rate/ Last Modified: 2020-03-05 (2020-04-27)

11. Geoff Brumfiel “Why Some COVID-19 Patients Crash: The Body's Immune System Might Be To Blame” Internet: https://www.npr.org/sections/health-shots/2020/04/07/828091467/why-some-covid-19-patients-crash-the-bodys-immune-system-might-be-to-blame Last Modified: 2020-04-07 (2020-04-27)