A new study suggests that human parasites—like fleas and lice—and not rats, may be responsible for spreading the Black Death that killed millions of people in Medieval Europe.
A personal favorite infectious disease of mine is the plague, what a perfect confluence of infection agent (the bacteria Yersinia pestis), susceptible population (do you know what passed as cleanliness standards in medieval Europe?), and good environmental factors (over crowding).
But it turns out that rats, previously thought to be the main culprits of spreading the plague, may not be responsible for spreading the Black Death (also, GREAT name).
Want to know more? Read about it here!