One of the things we learned early about COVID-19, was that a lot of the cases comes from so-called super spreader events. Events where a lot of people got infected, and then spread the virus after going home.

So far, the biggest super spreader event has probably been the Atalanta-Valencia Champions League match in February, which is thought to have pretty much been the reason for the rapid spreading in Italy. It could probably be considered a number of super spreader event. The actual football match at the stadium, where a lot of people got infected, but also the many gatherings of people watching the game, where many people undoubtedly got infected.

Back then, people at least had the excuse of not knowing any better. The virus was not yet well known in Italy, and few cases, if any, had been identified. This changed rapidly after the match, where Italy became one of the worst hit countries.

The same excuse cannot be made by anyone now, especially not in the US, which is one of the worst hit countries.

This is one of the things that makes this year’s Sturgis Motorcycle Rally such a baffling event. Who in their right mind would think it would be a good idea to gather nearly half a million people during a pandemic? Many of these people not even doing the simplest measures, e.g. masks and social distancing, to avoid the spreading of the COVID-19 virus.

Sadly someone obviously thought it was a perfectly acceptable idea, and allowed the event to go ahead.

Now, a study, The Contagion Externality of a Superspreading Event: The Sturgis Motorcycle Rally and COVID-19 (pdf), has evaluated the results of the rally, and have estimated that it has resulted in up to 219,000 infected people since the start of the rally, which is approximately 19% of all cases in the US during that period. Due to the diverse geographical origins of the participants of the rally, the spreading is not just in South Dakota where the rally took place, but in the surrounding states as well.

On top of looking at the spreading of the virus, the paper also estimates the financial costs to society. The paper estimates that the rally has cost more than $12B so far.

In other words, the human and financial costs of the rally is truly staggering, and is probably only going to grow, as time goes on.

Will this event be a lesson for other organizers and local authorities? One would think so, but sadly there is nothing in past behavior to indicate that this will be the case