BLACK DEATH
In this disease, the bacterium Yersinia pestis causes swollen lymph nodes in the groin, armpit, and neck. Other symptoms are suppuration and fever, producing chills and delirious in many people.
In the 14th century, the most common form of the disease was swollen lymphatic nodes. At that time, this organ was called bubo, and therefore the disease was called bubonic plague.
Y. pestis colonized rodents, particularly black rats, and it was transmitted through fleas (Chenopsylla cheopis) that lived on them. The fleas, by biting humans, inoculated the bacteria into humans. The frequent contact between them facilitated the infection and spread of the disease.
It is estimated that between 1347 and 1353, the Black Death reduced the European’s population from 80 million to only 30.
There were also other forms of the disease, such as the septicemic plague. In this case, the bacterium multiplies in the bloodstream. The signs of this disease were dark skin patches, which were the origin of the name “Black Death,” or “Black Plague.” The pneumonic plague affected the respiratory system and the symptoms included a productive cough that could cause airborne transmission.
