Ole Jørgen Benedictow

However, this is the good news.

Norwegian professor and Black Death expert, Ole J. Benedictow, who I've heard from a few times, he writes, however, contrary to what is sometimes believed, this form is not contracted easily, spreads normally only episodically or incidentally, and constitutes, therefore, normally only a small fraction of plague cases.

So, it's only a few percent actually contracted.

This mnemonic plague.