Understanding COVID-19: Episode 12 – Transmission of Coronavirus

By Bob Arnot, M.D., sponsored by DeVry University

April 2, 2020
3 min read

How exactly is COVID-19 spreading? Dr. Arnot states that the most common transmission of coronavirus is person to person (within 6 feet) and from surfaces, although that appears to be less common and with no documented cases. The video goes into detail about what surfaces the virus can live on and how long it stays active before dying out. The doctor also explains why this virus is spreading so quickly and how it can invade the host more easily than previous viruses.

Video Transcription

Let's look closer at transmission, the most common is person to person within six feet. Surfaces are less common and without documented cases. However, we'll look at how long viruses survive on various surfaces.

Patients start to show symptoms within a couple of days, but five days after exposure is most common for patients to fall ill. Why does corona spread so easily? Part of this may be microscopic features that allow it to invade the host more easily.

Children may prove a critical source of spread. The journal Pediatrics reported on 2,143 young people in China. The study showed that 90% of children have mild to moderate symptoms that might go unnoticed. Children may be super spreaders.

AEROSOL TRANSMISSION
The prestigious New England Journal of Medicine looked at means of transmission in China. There are two key means, the first was aerosol with person to person contact less than six feet. Droplets from the infected person were the primary means of transmission and would reach the nose or mouth of those around them. Prolonged suspended aerosol is not thought to be a primary means of transmission because the disease would be far more infectious.

SURFACE TRANSMISSION
The journal also looked at surfaces and found the following:

Steel

Went from 10 to the 3.7 initially and dropped to a 10 to the 0.6 after 48 hours
Plastic

From 10 to the 3.7 initially and 10 to the 0.6 after 72 hours
Copper and Cardboard

Proved safer with no viable virus after four hours for copper and 24 hours for cardboard.

TRANSMISSION
This chart shows how long the virus remains at what concentrations over time. In air, the virus gradually decreases over three hours. Looking at surfaces you can see the decay is faster for copper followed by cardboard, stainless steel, and plastic.

Disclaimer: The opinions expressed are those of the author. The content is intended to provide general information on the nature of the pandemic, potential exposures, and is not intended to provide medical advice or address medical concerns or specific risk circumstances. Always seek the advice of your doctor or other qualified health provider regarding a medical condition. Neither DeVry University nor its employees or business partners, nor any contributor to this content, makes any representations, express or implied, with respect to the information provided herein or to its use.

View the prior episode, Understanding COVID-19: Episode 11 – Mitigation Strategies