The fact that the plague decimated Europe’s population is always brought up, but I’ve never heard of any kind of illness of equivalent magnitude hitting civilizations in Asia or Africa. Were any of those cultures also severely affected by plague, or another disease, to the same scale as Europe? If not, why not?
I'm never the specialist either in Asia and in Africa, but the following previous questions and answers might satisfy OP's interest. In short, the plague outbreak around the middle of the 14th century certainly hit at least the latter, but the source problem prevented us from estimating the plausible figure.
(Edited): Fixed the broken link to the last question thread (thank you for /u/Commustar's notice)!