It’s been an uphill battle trying to get information out to control COVID-19, the disease caused by SARS-CoV-2.
Language is important. You’ll see how mass media seems to have largely rejected SARS-CoV-2, perhaps because it’s so unwieldy a name, and is confusing with SARS attached. So newspaper reports use coronavirus, which is fine, even if there are different types of coronaviruses.
Then there’s style, the need to banish as much jargon as possible and to use more imaginative images. I’m going to try that with today’s column, describing viral transmission as a Coronavirus Trek—yes, taking off from “Star Trek.”
Coronavirus trek, we will see, is phenomenal; this virus is able to travel through people’s bodies and through the air (but note, it is not, technically “airborne” or, in Filipino “nasa hangin”). Imagine, then, the virus itself being a spaceship, albeit a tiny one.
Here’s some math around the virus that you can use for your homeschool sessions. I’m going to use micrometers here, 1,000 of which you need to make one centimeter. The diameter of a strand of hair is 80 micrometers. The bacteria E. coli is 2 micrometers. Coronaviruses are 0.12 micrometers.
Viruses are not only tiny but also are unable to reproduce on their own, in a sense a parasite that needs a specific host.
In the case of the COVID-19 virus, it must first enter a human being, and it does this through the mouth, nose, and, surprisingly, the eyes. The virus must reach the throat and the lungs where those spikes find a perfect fit with sites on human mucous membrane cells. (Did you feel an itchy throat as you read that?)
Once the virus’ spikes latch on — kumapit — to our cells’ outer membrane, the virus can now hijack parts of our cells to reproduce themselves, the new viruses budding off from our cells in large numbers.
These viruses then mainly attack our respiratory system, particularly the lungs, which are so important for transporting oxygen. Besides the lungs, they attack the blood vessels and our defense and immune systems.
Viruses need humans to be able to survive, to reproduce… and to get into new victims. They are transmitted from one person to another when someone who is infected coughs or sneezes. Research is also showing clear evidence of transmission through talking and singing, and think of how it gets worse with force, as in shouting and karaoke. Through these activities, droplets are released through the infected person’s nose and mouth into the air. Consider the droplets as larger spacecraft for the viruses.
Sneezing tends to send droplets further out, but we also need to do something about what I call macho sneezing and coughing, much like volcanic eruptions raining out droplets.
No, the virus is not airborne in the sense of being able to travel through the air for a long period of time. What happens, though, is that in enclosed spaces with poor air circulation, droplets can stay suspended in the air much longer. One medical journal article looking at a cluster of infections within a restaurant reports that the air conditioning increased risks because the air does not circulate well.
From time to time, then, turn off the aircon and open those windows. We Filipinos are too paranoid about hangin.
Many of the droplets will eventually fall to the ground within about half an hour under laboratory conditions, the lighter ones staying suspended longer and, as I have just explained, also in enclosed spaces with poor ventilation.
We have another route of transmission, though, with droplets that fall on surfaces that are “high-touch” by humans: doorknobs, tabletops, computer keyboards, elevator buttons, even cell phones. On copper, the virus stays about four hours, on cardboard up to 24 hours, and on plastic and stainless steel up to three hours. But the numbers on these surfaces decrease with time.
An infection will depend on the virus entering our body through the droplets, especially if directly on the nose or mouth, but we also need to consider the viral load, which is why a doctor, nurse, or health worker is at greater risk with so much more exposure inside a hospital.
Then there’s a potential victim’s own immune systems, which is why more precautions are needed for the elderly, and people with other diseases that have weakened the body’s defenses.
There’s research, too, about different strains of the virus, differing in their virulence, and there might be a genetic component to explain why even young people might die from the infection, while some elderly people are able to survive.
On Friday: Who’s smarter?
The Inquirer Foundation supports our healthcare frontliners and is still accepting cash donations to be deposited at Banco de Oro (BDO) current account #007960018860 or donate through PayMaya using this link .
Subscribe to INQUIRER PLUS to get access to The Philippine Daily Inquirer & other 70+ titles, share up to 5 gadgets, listen to the news, download as early as 4am & share articles on social media. Call 896 6000.