Afaik alcohol was mainstream in Europe and elsewhere because water was unsafe to drink before water treatment plants and so low % alcoholic beverages were a mainstay in the culture for hundreds of years.

I'm afraid you're starting from a false premise. This is a popular myth which it is my life's work to kill, and for that, I refer you to my post on this specific topic.

Since the myth is already false, the rate of cholera need not be answered, but for the sake of thoroughness, a user who no longer wishes to be tagged has a post re water sources in the MENA region.