Why was the Bubonic plague so devastating and how does the disease evade the immune system?
The bubonic plague, caused by the bacterium Yersinia pestis, is known as one of the deadliest pandemics in human history killing millions of people in the Middle Ages. The illustration to the right identifies the panic of people during widespread bouts of plague infection. Untreated, the morbidity rate is 50% although with proper treatment the morbidity rate falls to 5%. The bubonic plague was one of the first strategically used biochemical weapons. In 1347 Mongol warriors attacking a European trade town, Caffa, fell victim to the effects of the plague. They decided to catapult dead plague victims over the town walls to infect the inhabitants. Understanding the causes of plague are still essential today due to bioterrorism threats and the fact that the plague is still around today with 10 cases of plague reported every year from the states of Arizona, California, Colorado, New Mexico, and Utah in the US alone and a total of 12,998 cases reported world wide during 1990-1995 1).
