FWIW, the issue is not limited to Germany.
Millions of Americans still can't give blood because of the Mad Cow crisis
While human cases have declined sharply since 2000, the disease can theoretically incubate for decades, and experts have warned that a second wave could break out. Until recently, it was impossible to test for.
In 1999, the FDA recommended deferring anyone who had spent six months in the UK from 1980 to 1996 (when the UK implemented extensive controls to contain BSE).
In 2001, it expanded deferrals to include anyone who
—spent five years in any European country but the UK between 1980 and the present
—spent three months in the UK from 1980 through the end of 1996
In 2015, an FDA committee considered clearing people who had spent time in European countries other than the UK, France, and Ireland. The proposal didn’t go through, with some members complaining about the risk model used or inconsistencies in how countries were treated.