How do you think people’s misconceptions about the causes of the Black Death affected the spread of disease?

People believed it was airborne

Explanation:

This is the reason plague masks exist.  People believed the disease was airborne originally, and did nothing to improve their living habits, as at the time under feudalism, things were rather dirty.  People through their waste onto the streets, and the average person did not have proper hygiene, meanwhile the disease spread through fleas, which would be brought about by rats.