1. Bubonic plague

2. Is caused by a germ called Pasteurella Pestis which lives in the blood of black rats and is found in the guts of fleas, that then hop onto the rats fur and bite the rat.
The flea then hops of the rat and onto the person which it bite and it also passes on the Bubonic Plague onto the human.

3. Some of the effects this has on the person are
Large boils which are called Buboes in the armpits or in the groin area or even behind the ears. These boils can be as big as apples and onions
After a few days, Victims will develop red and black spots.
Seven out of ten victims die within a week.