Throughout human history, there have been lots of contagious, deadly diseases that people have battled. And, before 20th-century advances in antibiotics and virology, even those diseases that are now entirely treatable were once even more deadly! Let us explore one of those diseases.Bubonic plague

The bubonic plague is a severe infectious disease caused by the bacillus Yersinia pestis. Also known as “The Black Death,” and “The Pestilence,” it has been around for centuries, with the very first instance being the Plague of Justinian that took place between 541–549 AD.

The Y. pestis bacteria spreads through infected fleas or small mammals, such as rodents, and is passed on to humans who are bitten or scratched. It is found all over the world, but since the bacteria was discovered in 1894, scientists soon developed ways of treating and preventing its spread, and it is now curable in most cases with things like antibiotics!

The Black Death (1346–1353) led to people developing public health measures like isolating sick people, quarantines, and doctors wearing protective clothing!

Bubonic plague: The incubation period of bubonic plague is usually 2 to 8 days. Patients develop fever, headache, chills, weakness and one or more swollen, painful lymph nodes (called buboes). This form usually results from the bite of an infected flea.

There have been other episodes of bubonic plague in world history apart from the Black Death years (1346-1353). Bubonic plague still occurs throughout the world and in the U.S., with cases in Africa, Asia, South America, and the western areas of North America. About seven cases of plague happen in the U.S. every year on average. Half of the U.S. cases involve people aged 12 to 45 years.

In the U.S., most plague cases in people happen in two areas: Northern New Mexico, northern Arizona, and southern Colorado, and another area involving California, southern Oregon, and western Nevada.