The coronavirus – specifically, COVID-19, comes from a large family of viruses
called by the same name and is one of the most common causes of the common cold.
We have all had coronavirus! Under a microscope they look like a crown hence the
name corona. SARS-CoV-2 is now the seventh type of corona virus. There are four
of these viruses which cause our seasonal colds and 3 others, MERS-CoV which
caused the Middle East Respiratory Syndrome, SARS-CoV which caused the
epidemic in China in 2003 and now this virus SARS-CoV-2.
How the Disease is Transmitted
The SARS-CoV-2 virus, similar to influenza, is transmitted by droplet spread,
which means that when someone who is sick with the disease sneezes or coughs, the
droplets which have the virus in them can enter the eyes, nose, or mouth of another
person. Once airborne, the droplets travel short distances, generally less than 3 feet
(1 meter) and drop rapidly to the ground. If any of the drops land on a nearby
uninfected individual and gain access to the eyes, nose or mouth, that person can
also get infected. An unaffected individual may also touch a surface or object that
has the germs on it and then touch their mouth, nose or eyes. One can see how an
ordinary surgical mask may not be as helpful in this circumstance as much as we
would anticipate, because one would have to cover the entire face including the eyes.
There is another way infections are transmitted, which is the airborne route. This
results from the cough or sneeze of an infected person, but the germ floats through
the air and stays there. Significantly no contact with the infected person is necessary.
In fact, the infected person may have already left the area. Importantly, germs on
surfaces can be killed quickly by disinfecting agents such as bleach or Lysol.
In terms of being contagious, we will compare SARS-CoV-2 to influenza. As we do
this, remember that this is called a novel coronavirus. The reason is that our immune
systems have never seen it before and none of us has any immunity to it at all. One
person with seasonal influenza may infect 1.3 people, while one person with SARS-
CoV-2 can infect 2-2.5 people and if they are super spreaders, they can infect a lot
more people. One of the major challenges with this disease is that many people who
spread the disease are asymptomatic. In other words, you may have a family
member, or a work colleague, or a casual contact who has none of the classic
symptoms at all, but they are walking around with the disease infecting others.