“How Long Will Coronavirus Live on Surfaces or in the Air Around You?” (NYT, 3/18/20):
The coronavirus can live for three days on some surfaces, like plastic and steel, new research suggests…
...Experts...offered additional warnings about how long the virus survives in air, which may have important implications for medical workers…
...The new study, published Tuesday in the New England Journal of Medicine, * also suggests that the virus disintegrates over the course of a day on cardboard, lessening the worry among consumers that deliveries will spread the virus…
...When the virus becomes suspended in droplets smaller than 5 micrometers — known as aerosols — it can stay suspended for about a half-hour, researchers said, before drifting down and settling on surfaces where it can linger for hours. The finding on aerosol in particular is inconsistent with the World Health Organization’s position that the virus is not transported by air...
* The NEJM article also reports that the coronavirus has a new name,:
A novel human coronavirus that is now named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (formerly called HCoV-19)
Airborne vs. droplet transmission; Direct vs Indirect transmission of viruses:
The types of transmission described below are not mutually exclusive...
Direct contact transmission requires physical contact between an infected person and a susceptible person and the physical transfer of microorganisms...
Diseases spread exclusively by direct contact are unable to survive for significant periods of time away from a host…
...Indirect contact transmission refers to situations where a susceptible person is infected from contact with a contaminated surface…
...Some diseases can be transferred by infected droplets contacting surfaces of the eye, nose, or mouth. This is referred to as droplet contact transmission…
...Airborne transmission refers to situations where droplet nuclei (residue from evaporated droplets) or dust particles containing microorganisms can remain suspended in air for long periods of time... These organisms must be capable of surviving for long periods of time outside the body and must be resistant to drying...Fortunately, only a limited number of diseases are capable of airborne transmission…
This morning, MSNBC interviewed Dr. Lynn Goldman, pediatrician and epidemiologist, dean of the School of Public Health and Health Services, George Washington University about this NEJM study, reported in the NYT: (Unofficially transcribed by me).
Interiewer: Can you walk us through this new study about the transmission of the coronavirus? Clarify some of this for us….
Dr. Goldman: This study which was carried out by the National Institutes, is an incredibly important addition to our study of how the virus is being spread. When we can appreciate that virus is an aerosol for a brief period of time, as well as a very long amount of time that it stays on surfaces...the more surfaces on which we have the virus, the more times that we are around people who are creating aerosols, even though they are in the air for a brief time, the more likely we are to catch the virus.
The thing that’s been difficult to understand is the fact that country after country, what we’ve learned is that the virus is being transmitted by people who don’t believe that they have symptoms...if the virus is just being spread by droplets, because most of us, if we’re creating droplets, know we’re doing that— so I think it’s helping us in two ways: One, to understand just why this virus is spreading much more readily than the original SARS virus, and second, why it is true that it seems to be being spread by people who have very few symptoms…