Strokes are not contagious and do not spread exponentially through a population, overwhelming the health care system all at once. Things like smoking and lung c

Strokes are not contagious and do not spread exponentially through a population, overwhelming the health care system all at once. Things like smoking and lung cancer, or lifestyle related metabolic disorders might cause a lot of health care cost down the road, but they don't cause highly synchronized hospitalization throughout the population. Some hypothetical, stroke-causing, meme-like behavior which can spread rapidly would have to be quite insidious to spread as effectively as COVID-19, cause a temporally correlated medical event, and not be self-limiting. The closest I can think of, off hand, are spikes in drug overdoses or things like suicide clusters. But those are examples are self-limiting, in that most people seem to recognize that they do not want to have that outcome.