Yersinia pestis facts for kids

Yersinia pestis is a bacillus. It is a bacterium. It has been identified as the infectious agent of bubonic plague. This bacterium also causes other forms of plague- Septicemic plague and pneumonic plague. These three forms of the plague have been responsible for a high death toll in many epidemics throughout human history. These diseases are believed to be the cause of the Black Death. Because of the Black Death, about one third (one of three) people in Europe died. This was between 1347 and 1353.

The bacillus was discovered by the physician Alexandre Yersin during an epidemic of the plague in Hong Kong, in 1894. Yersin worked for the Pasteur Institute at the time. Originally, the microoganism was named Pasteurella pestis. It was renamed in 1967.

Currently, three varieties of Y. pestis are known.

Historians are currently divided about the role of Y. pestis in the Black Death. Some historians said that the Black Death spread far too fast. Therefore, Y. pestis could not have caused it. DNA from Y. pestis has been found in the teeth of some of the victims of the Black Death. For this reason, Y. pestis must have been at least a factor in some (but not necessarily all) European plague epidemics. These references are probably not in Simple English.

• Genome information is available from the NIAID PathoSystems Resource Integration Center (PATRIC)

See also

In Spanish: Yersinia pestis para niños