Airborne Spread?

On March 10 sixty members of the Skagit Valley Chorale met for practice at the Mount Vernon Presbyterian Church in Mt. Vernon, Washington. The decision to gather was not taken lightly. The leaders of the Chorale pondered whether it was safe to meet.

Consider the historical context: In Kirkland, Washington, just an hour south of the Chorale’s meeting place on February 29, the nation registered its first death from Covid-19, a man in his fifties who had evidently caught the disease in the community. The man had no connection to travel in China.  Governor Jay Inslee declared a “state of emergency” for Washington State that same day, February 29. (This “state of emergency” directs state government agencies to pay attention. It frees up funds for the purpose. It does NOT direct any particular action on the part of citizens. Inslee’s “Stay Home, Stay Healthy” order came March 23, two weeks after the Chorale practice.) For epidemiologists and infectious disease specialists, alarm bells were ringing. The day before the Chorale met, on March 9, Nancy Messonnier, M.D., Director, National Center for Immunization and Respiratory Diseases at the Centers for Disease Control (CDC) gave a “Media Telebriefing” that reflects deep concern in the federal medical and scientific community. You can read the transcript, published the next day, here

On Friday, March 6, four days before the Chorale met in Mt. Vernon, Mr. Trump was still minimizing concern. Questioned as to whether he would continue holding campaign rallies (of thousands of supporters), he replied, “Well, I’ll tell you what, I haven’t had any trouble filling them.” In the same interview at the CDC laboratories he said there “were only eleven deaths” in the U.S. and he “wasn’t concerned.” Entirely against epidemiological understanding of likely exponential spread of Covid-19, Mr. Trump was exuding confidence in a television interview, suggesting he would continue to hold massive rallies.

The federal Chief Executive, the man supposed to lead the nation, Mr. Trump, continued to downplay the seriousness of the threat:

March 7: “No, I’m not concerned at all. No, we’ve done a great job with it.” — Trump, when asked by reporters if he was concerned about the arrival of the coronavirus in the Washington, D.C., area. 

March 9: “So last year 37,000 Americans died from the common Flu. It averages between 27,000 and 70,000 per year. Nothing is shut down, life & the economy go on. At this moment there are 546 confirmed cases of CoronaVirus, with 22 deaths. Think about that!” — Trump in a tweet.

What to do? The leadership of the Skagit Valley Chorale decided on March 6, reasonably it seemed at the time, to meet on March 10, but to exercise reasonable caution amid “stress and strain of concerns about the virus.” Surely, by March 10 they were even more concerned, even though our national leader was still in denial. When the Chorale members met they used hand sanitizer. They spaced their chairs. They each brought their own sheet music. They refrained from hugging and shaking hands.

Three days later, on March 13, three of the choir members developed a fever. In the next few days they and others reported feeling fatigued and achy, some with coughs and shortness of breath, some with nausea and diarrhea. In the end forty-five of the sixty choir members who attended the practice fell ill. Two member of the Chorale who attended the practice on March 10 died. 

This type of incident forms the bedrock of epidemiology. Sadly, there has not yet been a formal study, a minute dissection of the incident. Where was each person standing during the practice? Are their clues that might tell investigators who the asymptomatic (or very sparsely symptomatic) person was who unwittingly brought the virus to the practice? Where did that person acquire the virus? Was there something particular about that person that made them a “super spreader” or are lots of asymptomatic or pre-symptomatic Covid-19 carriers have this potential to spread the virus? This is the realm of the epidemiologist, the medical detective.

Have you ever stood in side-wise sunlight, talking with a person, observing them talk, and noticed fine droplets of spittle project into the air? If you haven’t, be on the lookout. It happens all the time. These fine droplets don’t stop happening because there is no side-wise sunlight to reveal them. 

Does choral singing project more droplets, even aerosols (droplets so fine they remain suspended in the air) than are projected in regular speech? That certainly seems reasonable, but that is not the point. The lesson of this incident is clear: Covid-19 can spread from asymptomatic or pre-symptomatic individuals by airborne transfer. We do not know how often; we do not know exactly how far; we do not know how prolonged an exposure it takes; we do not know how many people acquire the disease this way, but airborne spread definitely happens. 

Bottom line: When you encounter another person neither you nor they can know if they (or you) are spreading virus. Wash you hands frequently, keep your distance, and wear something over your nose and mouth, any commercial mask if you have one, a homemade mask (check out this and this), or a double bandana. At the very least, wearing something over your mouth and nose in those conditions will diminish droplet spread–that’s both  courtesy and protection for all concerned. Not getting this disease is all about odds, and the odds of catching it are diminished by not spreading droplets.

Remember and pass along this story and its links. There is no better teaching or remembering device than a story. Jesus taught in parables for a reason. 

Keep to the high ground,

P.S. Regardless of who said it, there is a lot of truth to this statement as regards the impression made by a story: “A Single Death is a Tragedy; a Million Deaths is a Statistic.” Even the most steadfast of deniers of reality and science, Mr. Trump, can be swayed by an incident that hits close to home, a personal story he heard (as well as body bags lined up at a hospital near his home town that he saw on TV) :

Trump’s latest tonal and tactical shift (and almost certainly not the last) was driven by several factors, both personal and political. Trump learned that his close friend, 78-year-old New York real estate mogul Stan Chera, had contracted COVID-19 and fallen into a coma at NewYork-Presbyterian. “Boy, did that hit home. Stan is like one of his best friends,” said prominent New York Trump donor Bill White. (Vanity Fair)