May 22, 2020
Rapid contagion makes a great movie device–the bite of a zombie, the bloodlust of a vampire, the sneeze that tells you a man is doomed. Always fast. Always fatal. No movie-goer would have patience with a plot where the victim might or might not get a fever in the next two weeks or so. But that’s more typical of the world we’re living in.
Viruses too reach us by their own preferred vehicles. Humans get rabies from the bite of an infected animal. West Nile virus is transferred from the blood of an infected bird to a human by the bite of a mosquito. This is a slow and haphazard way for a virus to travel. The first outbreak of West Nile Virus in the U.S. was in New York City in 1999. It took three years to reach California. But a virus strikes gold when it can skip the animal step and go directly from person to person. Then it can literally fly. Take influenza.
The flu spreads mainly through droplets that spray into the air when a person talks, coughs, or sneezes within about 6 feet of you. A person is most infectious about 3-4 days after getting the flu. They can be infectious a day before they show symptoms and up to a week afterwards. That’s an incubation period of 2 to 7 days. You can spread the disease before you know you have it. In fact you may never know you had it.
COVID-19 spreads through droplets as well, but it has an incubation period of 2 to 14 days. You are most contagious 1-2 days before you feel sick, which can be any time during the 2-week period. You may even be infected and not know it, but you can still spread it to others. The 2-week period of possible contagion is one reason why COVID spreads faster than the flu.
Another reason is that it’s new. Our immune systems are meeting it for the first time. The immune system’s ability to fight back depends on individual variables such as existing health issues, age, and heredity.
We are still learning about this new disease and how it spreads. Two recent articles caught my attention. (See the links under articles below) First, the CDC now emphasizes that the virus spreads mainly from person to person through droplets and downplays the spread from surface contamination. The CDC page now has two headings: “The virus spreads easily between people” with the person to person precautions and then “The virus does not spread easily in other ways,” where the CDC lists touching surfaces. https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/how-covid-spreads.html
The other article (in the WSJ) concerns the risk of spread in crowds or “superspreader events.” Studies have shown that loud speech produces enormous numbers of droplets that can spread the virus to nearby people. A study in Germany suggests that infections spread in crowds may be more serious and longer-lasting than ordinary infections passed between individual encounters. Packing people together, whether on subways or at football games exposes more people to more droplets more intensively and for a longer time than a casual conversation.
It makes sense. Articles are already coming out on reconfiguring gatherings of all kinds from concerts to office layouts. We redesigned security after 9-11. COVID will push us to redesign how we get together.
We can expect more articles on how events and gatherings will change as the knowledge about this virus evolves. It’s sometimes frustrating to see recommendations and requirements change as we have over the last two months, but the changes are an indication of how much is being learned as research continues.
Fortunately, investigation of coronaviruses didn’t begin yesterday. Today’s COVID-19 research is based on discoveries made during the outbreaks of MERS and SARS during the last twenty years. The knowledge we already have will be a major advantage as we go forward.
UPDATE: Now that summer’s coming, I’m going to slow down to a few days a week to give me time for gardening, phone calls, email, Zoom socializing, etc. Thank you for reading my column!
Today’s Notable Headlines
“Coronavirus ‘does not spread easily’ from surfaces, revised CDC website says,” NBC News, May 22, 2020. https://news.yahoo.com/country-reopens-remains-coronavirus-spread-212335789.html
“The CDC says coronavirus ‘does not spread easily’ on surfaces or objects. Here’s what we know,” USA Today, May 21, 2020. https://news.yahoo.com/cdc-says-coronavirus-does-not-164322728.html
“Superspreader Events Offer a Clue on Curbing Coronavirus,” Wall Street Journal, May 20, 2020. https://www.wsj.com/articles/superspreader-events-offer-clue-on-curbing-coronavirus-11589977873
” ‘Super-spreader’ events may be responsible for 80% of coronavirus cases,” Metro, May 20, 2020. https://metro.co.uk/2020/05/20/super-spreader-events-may-responsible-80-coronavirus-cases-12729855/
References for this article:
“Characterizing MERS and COVID-19 Disease,” NIH, April 22, 2020. https://www.niaid.nih.gov/diseases-conditions/characterizing-mers-cov-disease
“Why Covid-19 is worse than the flu, in one chart,” Vox, March 18, 2020. https://www.vox.com/science-and-health/2020/3/18/21184992/coronavirus-covid-19-flu-comparison-chart
From the CDC website:
Why am I doing this?
The coronavirus pandemic will be indelibly written on our memories just as the Great Depression or the Battle of Britain left their mark on past generations. It is my intention to journal the events of these days from three perspectives: as a retired medical technologist, a historian (Ph.D., 2014), and an ordinary person living through an extraordinary crisis.
You are on History’s Edge.