Plague

Excerpt

Plague is a zoonotic infection that has affected humans for thousands of years. In humans, the primary plague syndromes are bubonic, septicemic, and pneumonic. All of these result from infection with the gram-negative bacillus Yersinia pestis. The typical life-cycle of Y. Pestis starts within an insect vector followed by transmission to a mammalian host, typically rodents or other wild animals. Humans are only affected as incidental hosts. Despite this, Y. pestis is arguably one of the most important microbes in human history. It has caused three documented pandemics, with the “black death” in 14th century Europe leading to the death of up to 30% of the population. The most recent pandemic began in the late 19th century in Asia and India, and it continues today in Africa. Outside of this, the bacterium remains endemic in the Americas and Asia and also exists as a potential bioterrorism threat, spurring ongoing vaccine development.