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.
http://rarediseases.about.com/od/infectiousdiseases/ig/Pictures-of-Bubonic-Plague/hand-gangrene.htm
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.
http://www.unbc.ca/nlui/wildlife_diseases
_bc/plague_cycles.gif
History
• There have been three major pandemics of the plague.
– Mid 6th century, mid 14th century, early 20th century
• The most well known plague pandemic was in the mid
14th 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.
Sedlec Ossuary in Kutna Hora
http://neatorama.cachefly.net/images/200512/sedlec-ossuary.jpg
http://z.about.com/d/goeaste
urope/1/0/o/5/-//SedlicOssuary11.JPG
http://www.earth-photography.com/photos/Countries/CzechRepublic/Czech_KutnaHora_Ossuary1.jpg
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.
To Review:
The Plague Rap
Works Referenced
"CDC Plague Home Page - CDC Division of Vector-Borne Infectious Diseases
(DVBID)." Centers for Disease Control and Prevention. Centers for Disease
Control, June 2009. Web. 14 Apr. 2010.
<http://www.cdc.gov/ncidod/dvbid/plague/index.htm>.
Crawford, Dorothy H. Deadly Companions: How Microbes Shaped Our History.
Oxford: Oxford UP, 2007. Print.
Dell, Helen. "Microbiology: Perspectives on Plague." Nature Dec. 2005: 926.
Web. 12 Apr. 2010.
Dunham, Will. "Scientists Find Potential Weakness in Plague Germ." abc
News 26 Jan. 2007. Web. 12 Apr. 2010.
History Channel. "History Channel - The Plague." YouTube - Broadcast
Yourself. 21 Nov. 2008. Web. 3 Apr. 2010.
<http://www.youtube.com/watch?v=9IjhQDnoCcY&feature=related>.
"Yersinia Pestis." Plague Home Page. Web. 4 Apr. 2010.
<http://plague.emedtv.com/yersinia-pestis/yersinia-pestis.html>.