Deciphering COVID-19: The Basics
Updated: Jul 7, 2020
In an effort to illustrate the value of evidence based and non-sensationalized writing, I write the following series of blogs partly from my experience in public health and mostly after reading and learning what experts have said.
As we all know and have been directly facing the ramifications, COVID-19 has drastically changed the way we live and think about our health (as you can infer from our previous Blogs). It is a global pandemic of a massive proportion that we were completely unprepared for which has led to great economic and social distress worldwide. Currently, there has been a lot of discussion ongoing about how to reopen the world economy post COVID-19 but I think many of these discussions and even decisions, though warranted from an economic standpoint, seem premature. Given the extent of the COVID-19 outbreak worldwide, it is important to first understand how the virus began, why it is so dangerous, and why we cannot take any further steps lightly.
What is COVID-19 and how did it originate?
COVID-19 is a zoonotic infectious disease. Zoonotic diseases are diseases that start in another species then jump species to infect humans after which they pass between humans. Zoonotic diseases like COVID-19 can come from any species at any time in a myriad of ways. In recent years we have been seeing an influx of communicable and infectious diseases and specifically of zoonotic diseases. Zoonotic diseases can be transferred to humans both by direct and indirect contact with the source animal. For instance, we may come in direct contact with an animal’s fluids or fecal matter by an insect bite, by working with animals (livestock for example), or by eating the source animal. We can also be infected indirectly simply by being near the animal and touching anything the animal was in contact with.
In the last 30 years we have seen several major outbreaks of zoonotic diseases including SARS (another coronavirus), HIV/AIDS, H1N1, and Ebola most of which have had similar situations, albeit much smaller outbreaks. These diseases have come from different species like chimpanzees, bats, and birds. Recent outbreaks have led to a massive amount of spending on health interventions and the loss of countless lives of individuals who would have otherwise been healthy. These diseases have and will continue to persist if we do not learn to prevent their spread and to respect the environment in which we live.
COVID-19 is an infectious disease that affects the respiratory system. COVID-19, like other coronavirus diseases, is named after a physical attribute. Coronavirus cells have a crown like feature that is visible under a microscope, hence the use of the Latin word for crown (corona) in naming them. Since there are several coronavirus diseases with different symptoms and outbreaks, the current one has been labeled COVID-19; 19 being the year (2019) in which it first presented itself. The two other coronavirus diseases are SARS and MERS, both of which have had their own outbreaks in the last twenty years.
The U.S. Centers for Disease Control and Prevention (CDC) has recently updated symptoms associated with COVID-19 but from what has been seen, the major symptoms are fever, a cough, and difficulty breathing. For some the symptoms are minor and others have even been asymptomatic, but for high risk cases the breathing difficulty develops rapidly leading to complications such as pneumonia and respiratory failure. According to CDC, those with severe underlying conditions such as diabetes, lung, and/or heart disease are more likely to develop serious complications.
How does it spread and why did it spread so quickly?
According to CDC, COVID-19 spreads through close contact with an infected person. As far as current information is concerned, COVID-19 is most likely to be transferred through droplets breathed in through the air when in close proximity to someone infected who sneezes or coughs (within 6 feet). COVID-19 may also pass from someone who is infected but not facing any of the symptoms, but experts are unsure of how likely this is yet. There are also some studies ongoing on how prone people are to infection if they come in contact indirectly with an object that has droplets on it. However, most cases are suspected to be related to direct inhalation of infected droplets from a sneeze or a cough.
Novel diseases become a major problem if and/or when they spread to enough people. This allows the disease to survive instead of dying out at a smaller number of cases like SARS did after less than 10,000 thousand cases worldwide. After the first person is infected, an infectious disease slowly spreads to others depending on how many people the infected person is in contact with and how susceptible others are to the disease. Once a few people in one area are infected it is considered an outbreak. If it spreads to a few areas or regions in one country, it becomes an epidemic and if it becomes pervasive countrywide or travels beyond international borders it is called a pandemic. Unfortunately, COVID-19 crossed both domestic and international borders after the Wuhan outbreak and became a major global pandemic without much of the world even realizing it.
Ideally, the best way to curb a pandemic is to nip an outbreak in the bud early on. This requires figuring out someone is infected with a new and emerging disease, recognizing they are highly infectious, knowing everyone they have been in contact with, and quarantining the circle of infected/susceptible people immediately all of which must happen at a record pace. Ensuring that these actions happen quickly requires immense coordination and compliance, both within and between countries, with information passing quickly to federal governments from the state/provincial levels and then to other nations so that prevention measures are taken swiftly. Federal and local entities must also have the capacity and authority to enforce strong measures that will prevent spread and the support of a trusting public willing to comply for the common good.
In the case of COVID-19 the world did not have the opportunity to learn about the virus early. It is suspected that even though the Chinese government notified the world of the virus on December 31st of 2019, the first case may have been much before that. While China gave the impression it had the Wuhan outbreak under control, the rest of the world did not take precautions to check anyone at risk of exposure and quarantine them prior to allowing them to enter their countries and travel around freely. This allowed the virus to spread fast and far before the world began to take notice when enough people had suffered severe health consequences for it to be a cause for concern.
Identifying an infectious disease is also not easy since there are countless diseases out there and many with similar symptoms. It would be difficult for doctors to recognize a novel disease so quickly unless it has a really unique set of symptoms like with Ebola that can cause hemorrhaging all over the body. The severity and speed of the respiratory impact of COVID-19 is what has helped doctors identify that it is a different disease than we have seen before and even now doctors are identifying other common symptoms in real time. There is so much uncertainty among scientists even now who are cautious to make any rapid judgments until there is enough evidence to support their thoughts. Ironically, until enough cases present themselves it can be difficult to identify a novel disease and especially difficult to identify how it spreads and what it does to the body. Therefore, many early cases are often missed.
As more and more people are tested and studied, it is apparent there may have been way more cases than originally assumed and that some people had already been infected a long time ago. Since the virus was able to spread without proper surveillance, it became much more difficult to stop and quickly snowballed out of control. Once it has reached a point like it has now, it becomes extremely difficult to know exactly how many people are infected, without testing a significant portion of the population. Without being able to test so many people, it is even harder to track them and prevent them from spreading COVID-19 to more people.
Finally, not knowing enough about the disease and its first outbreak, made governments unprepared for the pandemic. Countries did not even know about the disease’s existence let alone about how much it may have spread and what its symptoms were. Until governments knew that COVID-19 was a deadly new disease with respiratory failure as a potential complication, they could not have known or predicted exactly what equipment would be needed to treat the ill and stop spread. Further had the pandemic been prevented and relegated to a small outbreak, there would have been no need for so many tests, contact tracers, masks, ventilators, oxygen tanks, or a shutdown anyway. This is why it is so imperative that country governments invest upfront in prevention systems that can stop novel diseases from becoming pandemics and causing economic failure.