Yersinia Pestis

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Yesinia Pestis
Yesinia Pestis is the bacteria that caused the Bubonic Plague in 1347 and marched across Europe killing many people. This bacterium can grow with or without oxygen making its expansion inevitable. Yesinia Pestis is able to survive for several months in cool, moist places like rodent holes. People in the United States can be infected by Yesinia Pestis each year from flea or rodent bites, it is estimated that 10 to 20 people are infected yearly. Bacteria transmission occurs in one or in all of these three ways: bites from infected fleas, direct contact with infected tissue or bodily fluids and inhalation of infected droplets. Yesinia Pestis bacterium begins its march of death through fleas, transferring over to rodents, then on to humans and finally dying off along with corpses.

There are two cycles to the plague Yesinia Pestis: Sylvatic Cycle and Urban Cycle. In the Sylvatic Cycle, pre-human infection begins in wild rodents who have received the bacteria from fleas thus beginning the cycle of death. Fleas feed on these rodents until the population is dead or they find a new food source. Yesinia Pestis is mostly transmitted to rats, mice, squirrels, prairie dogs, chipmunks, cats and dogs. Yes, cats and dogs. It’s no wonder why there are still cases of the Yesinia Pestis bacterium still infecting people today. Once a domestic rat or animal is infected the Urban Cycle begins and the plague rapidly spreads onto the human population. Humans are infected through rat or flea bites. When a person becomes infected with the bacteria, it begins to multiply in the lymphatic system, which is a component to the body’s immune system. The period of becoming infected and the start of symptoms is called the incubation period. Incubation lasts from 2-6 days while the bacteria is actively replicating. An infected person will show signs of infected lymph nodes and termed buboes, swelling of the lymph node. As well as bleeding under the skin and will go into septic...
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