The Black Death originated in Central Asia and spread from Italy and then throughout other European countries. Carried by the fleas on rats, the plague initially spread to humans near the Black Sea and then outwards to the rest of Europe as a result of people fleeing from one area to another.
A person usually becomes ill with Bubonic Plague 2 to 6 day after being infected.
Prevention is through public health measures such as not handling dead animals in areas where plague is common. Without treatment, plague results in the death of 30% to 90% of those infected.
Bubonic plague is an infection of the lymphatic system. usually resulting from the bite of an infected flea, Xenopsylla cheopis (the rat flea). In very rare circumstances, as in the septicemic plague, the disease can be transmitted by direct contact with infected tissue or exposure to the cough of another human.
This was a widespread epidemic of the Bubonic Plague that passed from Asia and through Europe in the mid fourteenth century. The first signs of the Black Plague in Europe were present around the fall of 1347. In the span of three years, the Black Death killed one third of all the people in Europe.
In the 21st century, the disease is most common in Africa.