I meant to add, part of the syndrome would be a tendency for public health officials to over-count real cases and assign COVID-19 as cause of death when in reality some unrelated cause was self-evident. I am not trying to say nobody caught the actual virus or died from that. But with the clusters in some settings, that also makes me wonder how much of that is auto-suggestion at work.
COVID-19 means COronaVIrusDisease 2019. It is, first things first, a DISEASE.
It is caused by a newly recognized virus, SARS-CoV-2. Given the fact that this virus has spread all over the world in five and a half months and infected probably 100 million or more people, it's reasonable to believe that SARS-CoV-2 has recently evolved, been created, or made the interspecies jump for some reason like filthy eating habits in China.
When this virus arrives at a location, around 20% of the people living there get infected in an incredibly short time. The virus is quite interesting in this regard.
Then, infections stop spreading - or at least, they stop spreading in epidemic fashion. Around 40%-60% of humans seem to have innate resistance to infection based on long-lived memory T-lymphocytes, perhaps from prior CoV infections.
But in places where 20% of the population get infected, most people do not develop disease.
It's wrong, now, to call the asymptomatic PCR+ people "COVID-19 cases", because they are not.