U.S. choir outbreak called 'superspreader event' in report

[Judi Lynn]

CARLA K. JOHNSON
Associated Press
MAY 12, 2020 7:14 PM

SHORELINE, Wash. — Disease trackers are calling a choir practice in Washington state a superspreader event that illustrates how easily the coronavirus can pass from person to person.

The act of singing itself may have spread the virus in the air and onto surfaces, according to a report from Skagit County Public Health published Tuesday.

“One individual present felt ill, not knowing what they had, and ended up infecting 52 other people,” said lead author Lea Hamner, calling the outbreak a tragedy.

Two choir members died of COVID-19 after attending the March 10 practice of the Skagit Valley Chorale. The rehearsal was held nearly two weeks before the state’s stay-at-home order.

More:
https://www.post-gazette.com/news/nation/2020/05/12/U-S-choir-outbreak-called-superspreader-event-in-report/stories/202005120158

[riversedge]

1. such a sad story.

[Harker]

2. I was singing in my car...

near sunset recently, and was surprised to see how many droplets were visible flying into the sunbeams.

[Igel]

4. Yeah, people don't stop to think.

When you're breathing, you're not expelling much by way of droplets. All the surfaces in your airways and nasal passages are relatively smooth. Water vapor is what you get, not particulates. When you're just walking along breathing regularly, that mask you have on to virtuously save other lives is completely pointless.

Coughing is explosive, as is sneezing. There's a closure, occlusion, and pressure builds up behind it. The occlusion is between two wet surfaces that don't have sharp edges, so when the occlusion is released there's a spray of droplets. The mask is good. I'd wear a mask and cover my face with my elbow.

Speech sounds come in different categories. Vowels are open. They're breathing, except that the vocal folds are vibrating--opening and closing. They produce a bit of spray, but that mostly is going to slam into the pharyngeal cavity walls. Mask or no mask, meh.

There are sonorants, where the airflow isn't interrupted. Things like m, n, l. Mask still doesn't do much duty.

Then there are obstruents. One group is the continuants, like s or "sh"--they've been called "slit consonants" because there's a slit made, air rushes through, and the surface irregularities produce noise. And some (usually) fine droplets.

The real problems are stop consonants, esp. aspirated ones. They even talk about them being "burst consonants" and you can clearly spot the gap between when the airflow's stopped and released if you measure things instrumentally. These are things like k, t, "ch". There's a fair amount of pressure that's built up and the release has the same kind of spray as a cough would have, but not as intense. The louder you speak, the greater the tension and pressure; the more crisply you speak, ditto. They're the ones that make people say things like, "say it, don't spray it." https://en.wiktionary.org/wiki/say_it,_don%27t_spray_it

Singing is just very clear, funny talking layered on top of pitch.

[Harker]

6. I'd never thought about it deeply.

I do enjoy loud, funny talking, though pitch is elusive for me.

[safeinOhio]

3. The Quakers have it down.

“No talking, singing or chewing gum, the Friends meeting has begun”.

[woodsprite]

5. I'm in a non-profit choral group, and we are cancelling our 2020-21 season.

Church is on Zoom, and we have been having soloists or family groups provide the music.

I’ve been in the choral group since I graduated high school, and I’m 57 now. I’m on the board, and we’ve been making arrangements to continue behind the scenes, business continuity as much as possible until we can be together again.