Yersinia pestis is a bacterium that causes bubonic plague, septicemic plague, and pneumonic plague. It is typically transmitted via the bite of an infected flea and causes swelling of lymph nodes called buboes. Bubonic plague is the most common form. If left untreated, it can spread to the bloodstream, causing septicemic plague, or to the lungs, causing pneumonic plague. Throughout history, plague pandemics have killed millions of people. Modern treatment involves antibiotics, but prevention through avoiding contact with infected animals and their fleas is important.

1. Yersinia pestisBy: Andrea RobertsonSepticemicPlaguePneumonic PlagueBubonic Plague

2. Rod-Shaped Facultative AnaerobeGram negative proteobacteria that causes Bubonic Plague

3. TransmissionBubonic plague is a serious, life-threatening disease, which is transmitted to humans when they are bit by an infected rat flea and causes death quickly. There are more than 100 species of fleas that have been reported to naturally be infected with the plague. Y. pestis is mostly found in rats but have also been found in other wild animals such as prairie dogs.

4. Global SignificanceThe World Health Organization reports 1-3,000 cases of plague each year. 1 in 7 people die from the disease. People under 20, especially men are more likely to get the plague.Researches have found that the plague causes more infections after warmer spring months and wetter summer months.

5. The first known pandemic was in 542AD and lasted about 60 years. This outbreak killed millions of people and most of the deaths were located in people living along the Mediterranean Sea.The second pandemic was in the 14th century. This was believed to be the worst outbreak of plague. It was known as the Black Death. This pandemic was located in central Aisa and lasted for 400 years. Villages were demolished and about a third of the European population died.The third pandemic was in 1894 and started in China and reached Canton and Hong Kong. The plague started spreading throughout the world and killed millions.

6. Bubonic PlagueBubonic Plague is an infection of the lymph nodes in the Lymphatic system which includes the tonsils, adenoids, spleen and thymus.Glands that swell are called buboes, which is how Bubonic Plague got it’s name. Buboes are found in the groin, armpit or neck and most often will occur close to the site of the initial infection and become red and swollen.

7. Bubonic Plague is the most common.

8. Transmitted from the bite of an infected flea or rodent.

9. Symptoms usually occur within 3 to 7 days of exposure.

10. Pain may occur before the actual swelling begins.

11. If bacteria is left untreated it can spread into the bloodstream and symptoms of septicemic plague may begin.

12. More symptoms include: chills, seizures and weakness.SepticemicPlague Transmission from a flea, rodent bite, or if bubonic plague is left untreated.

13. Symptoms include fever, chills, abdominal pain, rapid heart rate, vomiting, delirium, shock, and bleeding into the skin or organs.

14. Fingers, toes, and the nose may become gangrenous.

15. Infection in the blood.

16. Bacterium replicate in the bloodstream.