Covid 19: or Everything You Need to Know about the Modern Pandemic
Commonly called Coronavirus, Covid 19 has spread to over 300,000 people across five continents. With the death toll over 14,000, people are concerned that this pandemic might spin out of control. Many are treating this as a worst-case scenario and are paralyzed with fear. The truth is the two most important things are to stay calm and educate yourself. Unfortunately, everybody has a busy enough life without spending hours reading the latest research and checking World Health Organization updates. So I’d like to answer a couple questions:
What is it, how does it work, where does it come from, and how do I protect myself?
What Is It?
Covid 19 is a member of the Coronoviridae family of viruses. This group of pathogens gets its name from proteins surrounding the viral envelope that have the appearance of the rays of the sun. Solar Corona in turn get their name from the Latin for crown. Which is also where the popular beer gets its title (next time you have one check out the crown on the bottle).
Most Coronaviruses that infect humans are harmless. Considering Coronaviruses are responsible for 10-30% of the common colds each year it is entirely likely you have been infected by and survived a Coronavirus. Good job, we’re all really proud of you.
There have only ever been three serious types of Coronavirus outbreaks: the 2003 severe acute respiratory syndrome (SARS) outbreak, the 2012 Middle Eastern respiratory syndrome (MERS), and now the 2019 Coronavirus disease (COVID 19).
Covid 19, or Sars-cov-2 the sequel nobody asked for, presents as a mild infection or is sometimes asymptomatic for 80% of cases. 15% develop severe pneumonia and 5% develop critical pneumonia, the disease is fatal for 2% of cases.
The virus itself, like all other Coronoviridae, has a single strand of Ribonucleic Acid (RNA), an envelope made of a phospholipid bilayer (like our cell membranes), and distinct surface proteins for which it is famous. The single stranded RNA is what Coronoviridae have instead of double stranded DNA like we do. Coronaviruses specifically have genomes of about 26-32 kilobases, which is quite large for a virus.
How Does it Work?
First the disease must spread from a human or animal (more on that later) to another human. It does this by traveling in droplets of saliva and mucus that are expulsed from the mouth and nose when people sneeze and cough. These droplets can travel up to about six feet and endure on surfaces for up to three days. Once the virus gets into your lungs it can infect your cells.
Covid 19, like all viruses, isn’t really alive. Bacteria, which cause disease as well, are alive because they can make their own parts and produce their own energy. Viruses can’t move or reproduce without the host cell.
Viruses are very picky; they mostly only ever infect a specific set of cells from one species. This is because on the surface of the virus is something called Surface Proteins. All cells are covered with Surface Proteins and they’re used to attach to other cells, pickup nutrients, and communicate, as well as a bevy of other functions. The proteins that give Coronavirus it’s distinct appearance highjack surface receptors on the target cell to trick it into bringing the virus inside. Imagine that these proteins are all keys that only open one lock, well that lock is on the surface of the host. This is where we find the difference between most Coronoviridae: the locks on their surface.
Once a cell gets tricked into recognizing the virus it envelops it with the cell membrane. This bubble of membrane and virus becomes an endosome, which is typically acidic on the inside. In the acidic environment the Virus now knows it’s in the host and has the endosome release its RNA genome into the cytoplasm. The cytoplasm is the inside part of the cell where the metabolism and synthesis of cell parts take place. Viruses bounce around in there and hijack the machinery of the cell to reproduce.
In the cytoplasm there is a particular machine called a Ribosome. Ribosomes are an essential part of life. DNA in the nucleus is transcribed into RNA, the RNA is sent to the cytoplasm where Ribosomes read it and make Protein. This is known as the Central Dogma of Biology, and it’s pretty damn important. Covid 19, and all other positive sense RNA viruses, insert their own code into the Ribosome.
The viral proteins are then cranked out until there are enough parts for hundreds and even thousands of new viruses. These proteins then get stuck into parts of the cell called the Endoplasmic Reticulum (ER) and the Golgi Apparatus (GA). To simplify these two organelles are the packaging and distribution centers of the cell. After the viral proteins get stuck into the ER and GA, they break off pieces of them and use them as the viral envelope.
In the cytoplasm the RNA of the virus genome is replicated as well. The budded of envelopes assemble the virus and are released from the cell. The released brand-new viruses either go on to infect other cells or are coughed and sneezed out to infect other humans.
Where Does It Come from?
The scientific community doesn’t know where the disease originated for sure, but we do have some good ideas. Most epidemic diseases come from other animals. This is known as Zoonotic Transmission. Bacteria and viruses that infect a host are well suited to that specific animal and don’t have noticeable effects. Think about it, if you infect a host you want them to have a long and healthy life, so you can quietly replicate. If the host dies, then the pathogen will likely die with it. Dangerous new diseases happen when a pathogen well suited to one animal (pig, bat, or chicken) jumps to a different species. Once in the new species the virus will have different and devastating effects. The 2003 SARS epidemic started in cave bats in Hong Kong. Contact with these animals due to destruction of their habitat or poaching for food likely caused the jump to humans. The 2012 MERS came from camels which are used as pack animals and transportation in Saudi Arabia. Constant contact between the animals and their handlers resulted in the jump.
Covid 19, which is very similar to SARS, likely came from bats as well. Some researchers think it might have jumped to an intermediate species before making it to humans. Unfortunately, in the Hebei province where Covid 19 started exotic animal meat markets are quite popular. Vendors will have live animals of varying species stacked right on top of each other, presenting the perfect environment for the spread, mutation, and jump of viruses. Though it is too late to stop the genesis of COVID 19 we can prevent the genesis of new pathogens by making open air meat markets illegal all over the world. Luckily the Chinese government is putting in place policy to curtail these exotic animal meat markets.
So if you want to stop the spread of new and dangerous diseases don’t eat bats or other endangered species. Yes, even Ozzy Osbourne has to lay off the bat biting, it’s for the good of humanity. This really isn’t a problem for western countries, but deforestation is another major factor when it comes to Zoonotic Transmission. Displaced species are more likely to live closely with humans, increasing the chances of disease spread. Make sure to support business and politicians against the destruction of animal habitats.
How Can I Protect Myself?
WASH YOUR HANDS! This bit of advice will work for any epidemic. Ebola? WASH YOUR HANDS. Zombie apocalypse? WASH YOUR HANDS. Common Cold in the office? Actually, herbal tea might...SYKE THE ANSWER IS WASH YOUR HANDS! Of course, different diseases have different protocol for halting the spread of infection, but good hand-washing is perhaps the most important thing to do. Clean your phone as well, many bacteria and viruses can survive on its surface. The CDC estimates 18,000-46,000 people died in the US due to the flu. That is a number known in the scientific community as “too damn high”. It’s an order of magnitude more than the number of deaths due to Coronavirus. Many of these mortalities could have been avoided with proper hand washing and flu shots. Hopefully the lessons we learn from this crisis are well remembered.
That being said, there are specific precautions one can take to avoid Covid 19 Coronavirus. As mentioned in the How Does it Work section Covid 19 spreads through droplets released from coughing and sneezing. The first precaution is stay away from people who are coughing and sneezing. When applicable politely ask them to cover up. The WHO recommends a distance of one meter (metre?) or 3 feet. However, the CDC says that droplets can be carried up to six feet. So if you’re going to be cautious stay two arm lengths away from people. Also don’t shake hands, and if you do wash them before you touch anything else. I’ve heard people chide and mock the burial practices that can lead to disease spread in undeveloped countries then proceed to shake hands and give cheek kisses as greetings. It’s not impolite to forego handshaking if the flu or another disease is going around. Also avoid touching your face, nose, and eyes. You’d be surprised how difficult it is not to touch your face.
The rest of the precautions are ones that you should take if you do get sick. Cover up when you cough or sneeze. If you’d be upset with someone for spitting in your coffee, then don’t cough droplets into the air they breathe. It’s not only polite but it could save the world. Also, if you don’t feel well, stay home from work or social gatherings. If you have a fever, chills, or vomiting then call a healthcare professional and seek help. I know I like to tough it out when I get sick, but that can just lead to disease progressing to an unmanageable state.
If you do have to go out when you’re sick, please be considerate. Those silly looking masks that people wear are actually better at keeping a sick person from spreading the disease than preventing a healthy person from getting sick. If you don’t have the disease, you’ll still get the droplets on your hands and face. But if you’re sick the mask can keep any droplets from escaping you at all, protecting everyone around you. If you have to take public transport, consider how many people are within a 3-foot radius of you. Covering your face with a scarf or lower grade medical mask isn’t nearly as effective as the proper thing. If you don’t feel well and have to go out get yourself an N95 medical mask. Sure you might get stares but it’s both the polite and right thing to do.
What You Can Do to Help.
I didn’t mention this section in my introduction because I know that in these frightening times you just want to protect yourself and your loved ones. But the only way we can stop the spread of Covid 19 and other diseases is by working together hand in hand (only in spirit, don’t hold hands with people who are infected).
The first step is to remain calm. If you were in a movie theatre and someone screamed fire people would run madly for the exits. No one would be able to get out and everyone would get trampled. But if we remain calm, recognize the true danger, and act rationally we can prevent a lot of damage and save lives. This disease is terrifying, I admit it. As someone interested in microbiology, virology, and epidemiology I have long been afraid of such a pathogen. But it isn’t magic, it’s not some sort of curse, and this isn’t the middle ages, we have an arsenal of weapons at our disposal. It is a virus composed of protein, fat, and ribonucleic acid. It can be destroyed with heat, soap and water, alcohol, and antivirals. It’s spread can be halted by hand hygiene, personal hygiene, and social distancing.
The vast majority of us are already safe from it. Like most things in life those in danger are people who are already weak and susceptible. If you are immunocompromised or over 65 years old, it would be a good idea to stay at home and avoid other people. Caretakers should also treat themselves as if they are at risk. If your grandparent relies on you or if you have a family member with a disease like cancer, then treat yourself as if you were in danger. Avoid public places, avoid contact, and wash your hands religiously.
So what we need to do is keep soldiering on. If you’re not sick and have an essential job, please go to work. Stick to social gatherings under ten people, and respect social distancing and personal hygiene. Exercise is also good at combating disease. Even if Covid 19 Coronavirus spreads to every country and city the trains will still have to run, trucks will still have to deliver food, and the world will keep spinning. So remember do your part: don’t panic, educate yourself, and please wash your damn hands.
Bibliography and References:
World Health Organization Coronavirus 2019 Situation Report 63, 23rd March 2020
Bryan Lufkin, Psychology of Panic Buying, BBC,4th March 2020
Anthony R. Fehr, Stanley Perlman, Coronaviruses: An Overview of Their Replication and Pathogenesis, 6th January 2016
Interim Clinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19), CDC Website, 7th March 2020
Symptoms, Coronavirus 2019, CDC Website, 20th March 2020
Virology Lectures 2019, Dr. Vincent Racaniello, YouTube
Kristian G. Andersen, Andrew Rambaut, W. Ian Lipkin, Edward C. Holmes & Robert F. Garry, The Proximal Origin of SARS-CoV-2, 17th March 2020
Lin-Fa Wang, Zhengli Shi, Shuyi Zhang, Hume Field, Peter Daszak, and Bryan T. Eaton, Review of Bats and SARS, 12th November 2006
Harrath R, Abu Duhier, Sero-prevalence of Middle East respiratory syndrome coronavirus (MERS-CoV) specific antibodies in dromedary camels in Tabuk, Saudi Arabia, 26th April 2018
Navin Singh Khadka, Coronavirus: China wildlife trade ban 'should be permanent', BBC, 4th February 2020