On one hand side it's interesting that there are multiple records of this happening, but on the other these seem to come from "official sources". Which reminds me of an evening when we were dancing with friends at night (with candles around) to some quiet music in a city centre. Some police guy passed by after a while to check on a report of "Satanist dancing" (?) happening nearby. (Multiple tall, residential buildings had a good view on us) Of course that only led to us moving to a nearby park and making sure the candles form a pentagram this time - and dancing until early morning.
I can only imagine how would that night be described by random people - and how it could be misunderstood without context by anyone reading it hundreds of years later.
Also in 1930s, some people joined dance marathons which were pretty much an organised dancing plague with prizes: http://www.messynessychic.com/2017/08/29/the-depraved-dance-...
On the contrary, the expressions of underlying mental problems, which we call mental illnesses, are highly contagious. The DSM has a list of non-Western illnesses it calls "culture bound" syndromes, but we're becoming increasingly aware of how true it is for mental illnesses in general - even diseases like schizophrenia manifest differently in non-Western countries.
Wow, I've never been so embarrassed by someone dancing I've called the cops before. That's impressive.
Reading the article it feels like this is a combination of the 80's satanic panic mixed with a dose of evangelical convulsions and a dose of the Harlem Shake.