Yersinia pestis Ancient Plague and Modern Menace History

Yersinia pestis Ancient Plague and Modern Menace

History of Plague • Three major historical epidemics: 700 -600 BCE, 14 th-17 th C, 1855 present day • Black Death: 1347 -1351 • Recent Outbreaks www. tomecek. com/ jay/The. Plague. html

Present-day Relevance • World-wide spread • Bioterrorism • Re-emergence - Madagascar http: //www. cdc. gov/ncidod/dvbid/plague/world 98. htm

Hosts of Yersinia pestis • Mammalian http: //www. channel 4. com/history/ microsites/H/history/plaegu/plague. html Science Picture Library Human Rodent • Insect Xenopsylla cheopis www. exn. ca/Stories/ 2000/09/12/52. asp

Overview • Organism • Epidemiology • Transmission • Disease in Humans • Prevention and Control Center for Food Security and Public Health, Iowa State University, 2011

Yersinia pestis • Family Enterobacteriaceae – Gram negative – Pleomorphic coccobacillus – Aerobic, facultatively anaerobic, facultatively intracellular • One serotype – Three biovars • Multiple plasmids and virulence factors(F 1, Murine exotoxin, LPS endotoxin, coagulase, pesticin, plasminogen activator). Center for Food Security and Public Health, Iowa State University, 2011

Yersinia pestis • Destroyed by – Sunlight – Desiccation • Survival – 1 hour in air – Briefly in soil – 1 week in soft tissue – Years when frozen Center for Food Security and Public Health, Iowa State University, 2011

Transmission • Flea bite • Direct animal contact – Tissues, body fluids, scratches, bites – Enters through break in skin • Aerosol • Human cases – April through November – Increased activity of fleas and hosts Center for Food Security and Public Health, Iowa State University, 2011

Transmission Cycles www. pon. nic. in/fil-free/ vcrc/plague. html

Flea Transmission • 27°C (80°F) – Blood clots in gut of flea – Y. pestis trapped – Clotted blood regurgitated – Enters wound from flea bite • 27°C – Blood clot in gut of flea dissolves – Y. pestis passes through Center for Food Security and Public Health, Iowa State University, 2011

Center for Food Security and Public Health, Iowa State University, 2011

Human Disease • Three major forms of plague – Bubonic – Septicemic – Pneumonic • Primary • Secondary Center for Food Security and Public Health, Iowa State University, 2011

Bubonic Plague • Most common form – ~80% of cases • Incubation – 2 to 6 days • Clinical signs – Fever, malaise, chills, headache – Bubo: swollen, painful lymph node • Mortality (untreated): 50 -60% Center for Food Security and Public Health, Iowa State University, 2011

Septicemic Plague • Primary or secondary • Rapid onset • Clinical signs – Signs of sepsis ± bubo – Necrosis of extremities • Microthrombi block capillaries • “Black Death” • Mortality (untreated): 100% Center for Food Security and Public Health, Iowa State University, 2011

Pneumonic Plague • Incubation: 1 to 6 days • Primary—Y. pestis inhaled • Secondary—septicemic form spreads • Clinical signs – Fever, chills, headache, septicemia – Respiratory distress, hemoptysis • Person-to-person possible • Potential use as bioweapon Center for Food Security and Public Health, Iowa State University, 2011

Symptoms idcs 0100. lib. iup. edu/ West. Civ. I/the 8. htm www. imcworldwide. org/ cbr/L 1 C-m 2. html http: //aci. mta. ca/Courses/Biology/Images/bacterial%20 folder/Plague. htm • Bubonic • Pneumonic • Septicemic www. niaid. nih. gov/dir/ labs/lhbp/hinnebusch. htm

Diagnosis • “Diagnosis is based primarily on clinical suspicion” http: //www. cdc. gov/ncidod/dvbid/plague/p 4. htm • Staining • Serology • Culture www. einsamer-schuetze. com/natur/krankheit/pest/bedrohung. html

Treatment • Early treatment, survival ~100% • Supportive care • Antibiotics – Aminoglycosides – Doxycycline, tetracycline, chloramphenicol – Penicillins and cephalosporins are NOT effective Center for Food Security and Public Health, Iowa State University, 2011

Prevention and Control • Isolate infected animals – Limit number of people in contact – Personal protection • Surgical mask, gloves, eye protection • Flea control – Dogs and cats • Spring to fall – Environment • Vaccination Center for Food Security and Public Health, Iowa State University, 2011

Center for Food Security and Public Health, Iowa State University, 2011

Conclusion http: //www. witheridge-historical-archive. com/black-death. htm