Pestis and the People
Plague Forms
Pestis Effects

Pestis and the People

More than 20 million people died from the disease Yersinia pestis caused from 1347-1350.  However humans are always accidental victims. The fleas that transfer the bacteria prefer rodents and move on to humans only after their original host has died and become cold.

Photo: The Learning Company

Yersina pestis is named so because of its discovery by Swiss microbiologist Alexandre Yersin.  Yersin studied at Pasteur Institute in France.  In 1894 he isolated the pestis bacillus and concocted a treatment for what had been named Pasteurella pestis, after his institution of higher education, but which was later renamed as Yersinia pestis.


Paul-Louis Simond later proved that plague is transmitted by fleas.


The children's play song "Ring Around the Rosie" was actually created because of the Black Death.  "Ring around the Rosie" is in reference to the rings around the bite of the flea.  During that time people were carrying flowers called posies in their pockets to ward off the pungent smell of the plague.  So many people were cremated at that time, which is where "ashes, ashes" comes from and falling down was a metaphor for the death of the sufferer.

Image, Source: digital file from intermediary roll film
Photo: Library of Congress


Click here to see a slideshow of pictures from the plague of the middle ages.





Kristi Taylor