Causes
There are a lot of diseases with causes that defy easy analysis. My wife has multiple sclerosis, and they're still not sure why some people get it and others don't.
Off Topic » in reply to There's a difference between being infectious and being caused by a virus
There are a lot of diseases with causes that defy easy analysis. My wife has multiple sclerosis, and they're still not sure why some people get it and others don't.