Well, the Jews were not affected as much by the plague, because their religion had rules about them being clean and washing themselves regularly. Back in the time of the plague, most Europeans would not wash themselves often, so they would contract the plague much faster than people who were clean. It was somewhat looked down upon to clean yourself too, I believe. So anti-semitism would've been revived because the Europeans were upset about how the Jews were not being affected by the plague.
