Aletho News

COVID-19 Superspreader Events: Critical Patterns and Lessons

By Jonathan Kay | Quillette | April 23, 2020

… Of the 54 Superspreader Events (SSEs) for which underlying activities could be identified, only 11 did not involve either religious activity, a party, a funeral, a cruise or extended face-to-face professional networking. But even in this minority of cases, one can observe almost identical interpersonal dynamics. Three of the SSEs—in Japan, Skagit County, WA, and Singapore—involved concert-goers and singing groups belting out tunes together over a period of hours. (The Skagit example is particularly interesting, because the organizers were aware of the COVID-19 risk beforehand, and took the precaution of spacing out the participants by several feet. If they had been merely chatting, instead of singing, no one might have gotten sick.)

Another SSE involved a group of Canadian doctors engaged in a day of recreational curling. This is a sport that involves hyperventilating participants frenetically sweeping the ice with brooms while their faces are positioned inches apart, sometimes changing partners—an ideal climate for Flüggian* infection. Indeed, this partner-swapping aspect of the activity seems to be a common feature of many suspected SSEs, such as square-dancing parties.

Four of the SSEs were outbreaks at meat-processing plants, in which “gut snatchers” and other densely packed workers must communicate with one another amidst the ear-piercing shriek of industrial machinery. I lack the expertise to determine how the refrigerated nature of some meat-processing facilities may affect the dynamics of droplet transmission—though I would also note that at least four of the SSEs on my list unfolded at European ski resorts. But high levels of noise do seem to be a common feature of SSEs, as such environments force conversationalists to speak at extremely close range. (Related factors may be at play in old-age homes. These tend to be quiet places. But the reduced speaking volume and hearing functions of some elderly residents lend themselves to conversations held at much closer range than is socially typical in the general population.)

Finally, three of the SSEs involved mass sports spectacles, during which fans regularly rain saliva in all directions as they communally celebrate or commiserate in response to each turn of fortune. (Advance to the 8:30 mark of this video, showing euphoric hometown fan reaction during the infamous February 19th football match between Atlanta and Valencia, and you will see exactly what I mean.) As we now know, the danger starts even before the action begins: One of the most dangerous things you can do at a sports event in the COVID-19 era is sing the national anthem. … Full article

* As a 1964 report in the Proceedings of the Royal Society of Medicine put it, the quantity of expelled Flügge droplets varies markedly based on the manner of respiration: “Very few, if any… droplets are produced during quiet breathing, but [instead, they] are expelled during activities such as talking, coughing, blowing and sneezing.”

April 23, 2020 - Posted by aletho | Timeless or most popular | Covid-19