Yersinia pestis

Causes the black plague/death, occuring during the 1300-1800s. Estimated to cause 100 million deaths in the 14h century (roughly 1/3- 1/4 of the world’s population at the time). It was carried by fleas on rodents such as rats and prairie dogs. The plague can also be spread by coughing.
== Bubonic plague ==
Bubo refers to the lymphatic system, which swell up during the infection. Tissues turn black and there is a 80-90% mortality rate untreated.
== Pneuomonic plague ==
If the patient survives the bubonic plague, it can progress from lymphatic system to the lungs, and digests away the lung tissue. Black color and transmitted via coughing. Patients become cyanotic (blue) because they can’t breathe. The within rate is almost 100% if left untreated, and patients die within a few days. May have caused the delta 32 mutation in the CCR5 gene 
DOC = Mainly streptomycin, but sometimes include tetracycline(ex. doxycycline)