ALL NEWS

What is coronavirus and Covid-19? An explainer

Mar 31, 2020, 6:18 AM | Updated: 6:48 am
COVID-19 deaths...
This illustration provided by the Centers for Disease Control and Prevention in January 2020 shows the 2019 Novel Coronavirus (2019-nCoV). This virus was identified as the cause of an outbreak of respiratory illness first detected in Wuhan, China. (Centers for Disease Control and Prevention via AP)
(Centers for Disease Control and Prevention via AP)

(CNN) — Coronavirus. Just the word strikes fear into our hearts.

“Novel coronavirus” is the proper term for this brand-new virus wreaking havoc on our unprepared world.

But you can also call this nasty villain by its scientific name: severe acute respiratory syndrome coronavirus 2, or SARS-CoV-2 for short.

Becoming infected with SARS-CoV-2 can trigger a potentially deadly respiratory disease called Covid-19, an illness which presents with three main acute symptoms: fever, a deep, dry cough and a shortness of breath which can become quickly life-threatening. Other symptoms can mimic a cold or the flu.

Covid-19 seems to strike the elderly and immunocompromised the hardest, along with any of us with underlying health conditions such as diabetes, heart and lung disease. But the young shouldn’t take anything for granted — there have been numerous deaths among people aged 20 to 50, as well as a very few among children.

Covid-19 can also present with mild symptoms very similar to a typical cold or flu — or no symptoms at all, which makes controlling the spread of the virus causing Covid-19 very difficult.

What is a coronavirus?

All viruses are like zombies — they try to take over people’s bodies — but they aren’t really alive. Outside the host’s body they are dormant, surviving without living. Once touched or inhaled and brought inside, their ancient machinery springs into action, using proteins to latch onto and invade human cells.

There they set up shop, producing millions of copies of themselves and causing those cells to rupture. Like the famous scene from the movie “Alien,” the viral offspring shoot out into the bloodstream, with the goal of invading more and more cells.

As they multiply, humans began to spit them out into the universe with each exhalation, making us contagious days before we begin to cough, sneeze or have diarrhea — all symptoms the virus creates to ensure it can leap from human to human, thus ensuring its survival.

This “virus zombie invasion” comes in all sort of shapes, sizes and genetic strategies. All coronaviruses are covered with pointy spires of protein, giving them the appearance of having a crown or “corona” — hence the name. Coronaviruses use these spikes to latch onto and pierce our cells.

Coronaviruses are part of the RNA brigade of viruses, which are much less stable than their DNA-based comrades. Why is that important? Because instability leads to mistakes in copying genetic code.

That leads to mutations — thousands, millions, billions of mutations. Sooner or later, one mutation hits pay dirt and allows the virus to cross the great divide between different species. A few million/billion/trillion more mistakes creates another mutation that allows that virus to spread easily. Now the virus is both in its new host and it is contagious.

It’s that type of mutation which gives humanity viruses like SARS-CoV-2.

Where did the novel coronavirus come from?

The animal kingdom is teeming with coronaviruses. They are found in cats and dogs, pigs and cattle, turkey and chickens, mice, rats, rabbits and of course, humans. Insects too.

Some of those coronviruses can cross species, such as between pigs, cats and dogs, but for the most part coronaviruses stay loyal to their original hosts. Until, of course, they become that lucky mutation.

“Usually viruses from one animal really don’t effectively transmit to other animal species or even to people,” said Dr. John Williams, chief of the division of pediatric infectious diseases at the University of Pittsburgh Medical Center Children’s Hospital of Pittsburgh.

“So usually if a virus goes from an animal to a human, it’s sort of dead end. That person gets sick but it doesn’t spread further,” said Williams, who has studied coronaviruses for decades.

Besides the newly hatched novel coronavirus, there are actually six additional coronaviruses that infect humans — four of them cause the common cold.

Two more can be deadly. MERS-CoV is the villian behind Middle East Respiratory Syndrome, or MERS, which has killed over 800 people worldwide since it first appeared in 2012.

SARS-CoV causes a serious form of pneumonia that can also be life-threatening. Globally, it killed 774 people between 2002 and 2004. No other cases have been reported worldwide since. {To put that into context, the death toll of the novel coronavirus since it burst on the scene in December is approaching 40,000).

The coronaviruses that cause MERS and SARS are though to have crossed from mammals to humans, where they mutated to become contagious. MERS-CoV first appeared in Jordon and Saudi Arabia in 2012 and it’s thought to have crossed over to humans from dromedary camels in Africa, the Middle East and southern Asia.

“MERS is extremely deadly, about 30% of people who are infected with MERS will die,” Williams said. “So the virus got over one of the barriers — it’s able to infect humans, grow in them and cause disease — but thankfully it really doesn’t spread well person to person, other than very, very close contacts.”

SARS has been more difficult to pin down.

Because one of the most common carriers for coronaviruses are bats, it’s thought that the virus may have started there. Then it supposedly mutated to the masked palm civet, a small cat-like mammal eaten in some parts of China. But even that theory is disputed.

“SARS caused death in about 10% of people that became infected and it did spread person to person but not super effectively,” Williams said. “There weren’t many people walking around without symptoms or with mild symptoms, who could be spreading it.

“This new virus, SARS-CoV-2, has overcome more barriers,” Williams added. “It spreads easily person to person and a lot of people can have either mild disease or they might not even have symptoms, yet they can have the virus and spread it.”

The novel coronavirus appears to have originated in bats. A study published in February found the coronavirus found in bats shared 96% of the same genetic makeup as the novel coronavirus. But it wasn’t a direct link, so the bat had to have infected another species, which then infected humans.

Early reports pointed to snakes bought at a “wet market” in China were people buy live animals to eat. A recent report of the initial cases of coronavirus in China debunks the “snake flu” theory, reporting that in 13 of the 41 early cases the infected patients had no link to the wet market.

A recent hypothesis claimed the intermediate host was the pangolin, an endangered scaly, ant-eating creature beloved for its meat and scales, which are used in traditional Chinese medicine. But critics have been skeptical, sending genetic scientists back to their labs to continue the search.

At this time, scientists don’t know where the novel coronavirus began.

“These things are more difficult than [identifying] dinosaurs, because there’s no fossil record of a virus,” Williams said. “For example, the main virus I study, human metapneumovirus, is clearly a virus that has circulated in humans for decades if not a few centuries.

“However, when you look at the genetics of the virus, its closest genetic relative is a bird virus,” he added. “So, did that virus jump to humans way back and become established? That’s what we think. But it isn’t impossible that a human virus jumped to birds and became established there.”

The-CNN-Wire
™ & © 2020 Cable News Network, Inc., a WarnerMedia Company. All rights reserved.

Today’s Top Stories

All News

Defense Secretary Lloyd Austin extremism...
Ellie Kaufman, CNN

Defense secretary condemns ‘nuclear saber-rattling’ but says he doesn’t believe Putin has decided to use nuclear weapons

While U.S. Secretary of Defense Lloyd Austin hasn't seen anything to suggest Russia has decided to use nuclear weapons, he did condemn nuclear saber-rattling
11 hours ago
Hurricane Ian survivor Hope Labriola waited for help as her home filled with water. Photo credit: H...
Caroll Alvarado, CNN

‘I can’t do this’: Fort Myers Beach woman calls for help as Hurricane Ian’s storm surge floods her home

A Fort Myers Beach woman called for help as the storm surge from Hurricane Ian.
11 hours ago
Lisa Garner. Photo credit Draper City....
Mark Jones

Lisa Garner has support of Draper mayor to become next city judge

Draper Mayor Troy Walker is seeking the appointment of Lisa Garner as the city's next judge. The appointment must be approved by the city council on Oct. 4.
1 day ago
Two Murray police cruisers are shown...
Mark Jones

Murray Police warning public to be on lookout for scam

Several reports of a scam have been reported in Murray. According to police, a caller pretends to be from the Murray Police Department and attempts to notify a person of a warrant and insists the person pay the bail amount.
1 day ago
An electronic sign on the campus of the University of Utah was seen displaying pornography today....
Becky Bruce

Slight increase in crime on U of U campus from previous year, report says

There has been a slight increase in crime on campus over the previous year, according to a report released Friday by the University of Utah.
1 day ago
Turkey and cattle farms near Moroni, Utah. Three additional cases of avian influenza have been conf...
Mark Jones

Three additional cases of avian influenza confirmed in Sanpete County

The Utah Department of Agriculture and Food announced Friday that three additional cases of avian influenza have been confirmed on turkey farms in Sanpete County.
1 day ago

Sponsored Articles

Young woman receiving laser treatment...
Form Derm Spa

How facial plastic surgery and skincare are joining forces

Facial plastic surgery is not only about looking good but about feeling good too. The medical team at Form Spa are trained to help you reach your aesthetic outcomes through surgery and through skincare and dermatology, too.
large group of friends tohether in a park having fun...
BYU MBA at the Marriott School of Business

What differentiates BYU’s MBA program from other MBA programs

Commitment to service is at the heart of BYU’s MBA program, which makes it stand out among other MBA programs across the country.
a worker with a drill in an orange helmet installs a door in the house...
Price's Guaranteed Doors

Home improvement tip: Increase the value of your home by weatherproofing doors

Make sure your home is comfortable before the winter! Seasonal maintenance keeps your home up to date. Read our tips on weatherproofing doors.
Curb Appeal...
Price's Guaranteed Doors

How to have the best of both worlds for your house | Home security and curb appeal

Protect your home and improve its curb appeal with the latest security solutions like beautiful garage doors and increased security systems.
A paper reading IRS, internal revenue service is pictured...
Jordan Wilcox

The best strategies for dealing with IRS tax harassment | You have options!

Learn how to deal with IRS tax harassment. This guide will teach you how to stop IRS phone calls and letters, and how to handle an IRS audit.
spend a day at Bear Lake...
Bear Lake Convention and Visitors Bureau

You’ll love spending the day at Bear Lake | How to spend a day at Bear Lake

Bear Lake is a place that needs to be experienced. Spend a day at Bear Lake.
What is coronavirus and Covid-19? An explainer