The Great White Plague
Picking up where the Black Death left off, 17th century Europe found itself combating a microscopic monster responsible for the death of roughly 30% of its population. And this struggle lasted for (hold on to your underwear, now) an unprecedented 200 years! Mycobacterium tuberculosis, the bacteria behind the Great White Plague, was difficult to avoid as coughing, sneezing, or making some neighborly smalltalk were all, unwittingly, methods of transferring the disease. And similar to the circumstances surrounding the Black Death, close quarters and general filthiness contributed to TB’s spread. You’d think Europe would've learn something the second go-around, but no.