Confirmed: Y. pestis bacteria caused the Black Death

A very interesting blog post from The History Blog (click on above title for link) concerning the (now-known) microbial origins of the Black Death. Yersinia Pestis, the causative pathogen, is known to infect hosts, such as rats and fleas, and then be transmitted to humans. The three known types of plagues (i.e. bubonic, pneumonic, and septicemic) were responsible for countless deaths in the European continent over a period of 400 years. The list of symptoms for each type are listed below and are relatively severe and gruesome. Each of them had a mortality rate over 75% with the most severe type, septicemic, killing nearly 100% of those it infected.
Bubonic plague
-Incubation period of 2–6 days, when the bacteria is actively replicating.
-Universally a general lack of energy
-Fever
-Headache and chills occur suddenly at the end of the incubation period
-Swelling of lymph nodes resulting in buboes, the classic sign of bubonic plague. The inguinal nodes are most frequently affected (“boubon” is Greek for “groin.”)
Septicemic plague
-Hypotension
-Hepatosplenomegaly
-Delirium
-Seizures in children
-Shock
-Universally a general lack of energy
-Fever
-Symptoms of bubonic or pneumonic plague are not always present
Pneumonic plague
-Fever
-Chills
-Cough
-Chest pain
-Dyspnea
-Hemoptysis
-Lethargy
-Hypotension
-Shock
-Symptoms of bubonic or septicemic plague are not always present
