Presentation on theme: "The Plague Y. pestis Matt Cowper Katie Pazur https://publicaffairs.llnl.gov/Images/pestis_big.jpg."— Presentation transcript:
The Plague Y. pestis Matt Cowper Katie Pazur https://publicaffairs.llnl.gov/Images/pestis_big.jpg
Yersinia pestis Yersinia originally classified in Pasteurellaceae family – Based on DNA similarities with E. coli, Y. pestis is now part of Enterobacteriaceae family 11 named species in genus 3 are human pathogens – Y. pestis, Y. pseudotuberculosis, Y. enterocolitica – Y. pestis and Y. pseudotuberculosis rarely infect humans – Y. enterocolitica is the cause of 1 – 3% of diarrhea cases caused by bacteria
Yersinia pestis Gram-negative bacteria Can grow with or without oxygen Most commonly found in rats but also found in: – Mice, squirrels, fleas, cats, dogs, lice, prairie dogs, wood rats, chipmunks
Types of Plague Bubonic Plague – Most common – Infection of the lymph system (attacks immune system) Pneumonic Plague – Most serious type of plague – Infection of the lungs leading to pneumonia – Primary and Secondary Septicemic Plague – Bacteria reproduces in the blood – Can be contracted like bubonic plague but is most often seen as a complication of untreated bubonic or pneumonic plague
Symptoms – Bubonic Fever, headache, chills, weakness, swollen and tender lymph glands – Pneumonic Fever, headache, weakness, rapid onset of pneumonia (usually accompanied by: shortness of breath, chest pain, cough, bloody or watery sputum) – Septicemic Fever, chills, weakness, abdominal pain, shock, bleeding underneath skin or other organs Diagnosis and Treatment – Most cases of plague are diagnosed initially from presented symptoms, especially Bubonic plague. If plague is suspected, blood work is completed to determine how far the plague has progressed and to determine antibiotic resistances. – Since no major antibiotic resistances have developed, plague is usually treated with Streptomycin. Other antibiotics that can be used are: tetracyclines, fluoroquinolones and other aminoglycosides. – Antibiotics are administered to the patient as well as to those who are believed to have been exposed.
Transmission Bubonic and Septicemic can not be transferred human to human. They can only be contracted if bitten by an infected rodent or flea. Pneumonic can be transferred through exposure to infected particles. This usually occurs when in close contact with someone who is infected and is exposed to sputum that is coughed up.
History There have been three major pandemics of the plague. – Mid 6 th century, mid 14 th century, early 20 th century The most well known plague pandemic was in the mid 14 th century in Europe known as the Black Death – The plague came from Asia and spread through Europe in two years. – In the two years, it killed more than half of the population. – People didn’t understand how the plague worked which allowed it to spread. – Benefits.
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Incidence Considered a re-emerging disease. – Incidence is on the rise: 2,000 to 3,000 cases a year worldwide. http://www.cdc.gov/ncidod/dvbid/plague/world98.htm
Current Research at UNC While the plague isn’t causing major problems amongst humans and it is easily treatable, scientists are beginning to consider its potential use as a bioweapon. Here at UNC, Dr. William Goldman is studying the mechanisms of plague. – Using a mouse model, they are studying the progression of Pneumonic Plague and are working on determining how to slow its progression so it can be more effectively treated.