This is the scary number of people ‘superspreader events’ infect

High-risk coronavirus scenarios, commonly referred to as  “superspreader events,”  are potentially responsible for 80% of new transmissions. 

The coinage began appearing among medical communities following a two and half hour choir practice attended by 61 people, (including an asymptomatic index patient) that resulted in a communal spike in positive COVID-19 cases.

Thirty-two attendees contracted the SARS-CoV-2 virus, 20 were identified as probable secondary cases,three patients were hospitalized, and two died. 

“Transmission was likely facilitated by close proximity (within 6 feet) during practice and augmented by the act of singing,” The CDC’s Morbidity and Mortality Weekly Assessment reported.”The potential for superspreader events underscores the importance of physical distancing, including avoiding gathering in large groups, to control spread of COVID-19. Enhancing community awareness can encourage symptomatic persons and contacts of ill persons to isolate or self-quarantine to prevent ongoing transmission.”

Over the memorial day weekend, a photographer succumbed to COVID-19 after contracting the coronavirus at a wedding in Ramachandrapuram in India. Before dying,  the 60-year-old passed SARS-CoV-2 to 30 people in G Mamidala village of Kakinada district’s Pedapudi mandal. As a result, three regions in two mandals are now official red zones.

Medical experts have yet to offer an official list of super-spreader activities as we enter the summer months in the US, but the features that define them are available for review.

How to assess superspreader events 

“The fewer number of people at any gathering the less chance that any one of those people is going to be infected with COVID-19 and potentially spread it to all the other people in the group,”  explained Bert Jacobs, professor of virology at Arizona State University,

Although precautions are recommended whenever leaving your home, party volume defines a superspreader event the most reliably. 

If we interpret COVID-19 transmission risk as an equation, people can be likened to variables. The greater the variables the greater potential outcomes.The greater the potential outcomes, the greater the likelihood of adverse outcomes. 

Activities like indoor dining, grabbing drinks at a bar, house parties, attending a movie theatre and going to the gym, introduce the potentiality for asymptomatic/pre-symptomatic carriers to infect a vulnerable pool of host in a crowded public space with poor air circulation for an extended period of time. 

Additionally, a larger crop of unconfirmed cases means some are not going to practice social distancing for the entire duration of festivities.

“Outdoors you have more air circulation so any droplets that might contain the virus just get diluted out in the air as it is circulating around. Indoors those droplets are gonna sit there because there’s a lot less circulation,” Jacobs continued.  

The Kitzloch bar in the Tyrolean Alps, famous for their ski parties, recently became a high-risk superspreader event after spawning hundreds of coronavirus infections throughout Britain, Germany, Iceland, Norway, and Denmark. 

An independently conducted South Korean study determined that “Intense physical exercise in densely populated sports facilities could increase risk for infection” of the coronavirus. More directly, 112 people were infected with the virus within 24 days after participating in “dance classes set to Latin rhythms” at 12 indoor locations.

“Whenever we get together and we don’t have social distancing there’s a risk that if somebody is infected that they are going to transmit it to other people,” Jacobs concluded. “I think there are two things they need to think when they think about the risks they are willing to take, they can think about risks for themselves and their family but they also need to think about the risk for society as a whole and that’s where it gets really difficult.”

CW Headley is a reporter for the Ladders and can be reached at cheadley@theladders.com