Understanding the COVID-19 Pandemic

coronavirus, covid-19


Living with a chronic lung disease during a pandemic can be a scary thing. Whether you are an informed patient with a chronic lung condition or a member of the treating healthcare team, this blog series is meant for you. We will be tackling common and important topics, tailoring our content to you – our valued reader – with the main goal of keeping you informed and up to date. Today’s blog will introduce the Coronavirus disease 2019 or COVID-19 pandemic. This will lay the foundation for future blog entries that will explore high yield, dedicated ‘sub-topics’ in more detail.

What is a Pandemic?

The language buffs amongst you will know that “-demos” is Greek for “people” or “the people”. While “epi-” is Greek for “above” or “upon” (epidemic: upon the people), “pan-” is Greek for “all” (pandemic: affecting all peoples). That is to say, if an illness affects a community or region beyond what is normal or expected, it is an epidemic; but if an illness affects many regions and nations at once it is a pandemic.1 While the epidemic started on December 11, 2019, on March 11, 2020 the World Health Organization declared the novel coronavirus outbreak as a global pandemic.

What have we learned from previous pandemics?

The history buffs amongst you will know that the world has faced prior pandemics. The last global pandemic of similar scale was just over a century ago and was known as the 1918 Pandemic Influenza or the Spanish Flu. The similarities between that pandemic and the current pandemic are striking. That pandemic was also caused by a virus; the main treatment approach was supportive; and the risk of person-to-person spread (the contagiousness or ‘transmissibility’) was  high.2

While in 1918 global spread was influenced by the international migration patterns of World War 1 soldiers and paramilitary, in 2020 the remarkably global and interconnected world in which we live creates an established network for worldwide spread. We are fighting a virus that is highly contagious and has no cure, and so prevention of spread is one of the most effective tools we have so as not to overrun our health systems all at once. It is for this reason that you probably find yourself reading this blog in some form of social isolation, and that we all continue to practice social distancing.

Coronavirus Pandemics

Shifting focus from last century to this one, each of the last two decades of the 21st century witnessed viral outbreaks that are worth mentioning. The first decade saw the Severe Acute Respiratory Syndrome (SARS) coronavirus while the second decade saw the Middle East Respiratory Syndrome (MERS) coronavirus.3 In our current pandemic, the responsible virus is also a coronavirus: the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), and it causes the illness of Coronavirus disease 2019 (COVID-19). This virus causes symptoms that are highly variable and can range from no symptoms at all to death. In one of the first major identifications of  this virus in the medical literature, affected patients experienced cough and fever; pneumonia; and 1 of the 3 reported patients had died.4 Many of the first cases were linked back to a wholesale ‘wet’ market in Wuhan, China. 

Indeed, each of the three coronavirus outbreaks in the 21st century have been zoonotic, meaning infectious spread occurred from animal to human (a plug for our language buffs: “zoon” is Greek for “animal”!). Wet markets create an opportunity for a wide range of domestic and exotic wild animals (including bats and civets) to be in very close contact with one another, and moreover for large groups of humans to interact with these animals as well.5 The bat is the natural reservoir for SARS, MERS and SARS-CoV-2; SARS-CoV-2 is 96% identical (at the whole-genome level) to a bat coronavirus; and it is closely related to the SARS virus, and to a lesser extent to the MERS virus.4,6

In summary, the “pan” of pandemic rings true: the COVID-19 outbreak affects us all. A century after the Spanish Flu, we once again face a pandemic that is deadly and has no cure. Then as now, the emphasis must be on preventing the spread across our communities and around the world. A priority of our healthcare systems and our public health departments is to protect those who would be most vulnerable to bad outcomes from getting the virus, and to minimize bad outcomes as much as possible for all people.

Thank you for reading!

Profil picture of Dr. Bryan Ross

About the author

Bryan completed his medical school and Internal Medicine residency at the University of Toronto, and his Respirology fellowship at the University of Alberta. Prior to this he completed his undergraduate degree at Queen’s University and his master’s degree in Physiology at McGill University. He has had a longstanding clinical and research interest in respiratory and cardiac physiology and applied exercise science, in pulmonary rehabilitation, and in the management of chronic respiratory disease. He is currently completing an additional fellowship at the Montreal Chest Institute (McGill University Health Centre) in pulmonary rehabilitation and chronic disease management.

Dr. Bryan Ross