Transcript THE BLACK PLAGUE

THE BLACK
PLAGUE
The Italian writer Boccaccio said
the Plague’s victims often…
 "ate
lunch with their friends
and dinner with their
ancestors in paradise."
The Microscopic Killer
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Yersinia pestis
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Discovered by
Alexandre Yersin, a
French bacteriologist
in 1894.
LYMPH NODES
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The Black Plague attacks
the body’s “lymph nodes.”
Lymph nodes are a part of
the immune system. They
are sometimes called
"glands,“
The purpose of lymph
nodes is to protect the
body from "foreign"
invaders. These invaders
may be bacteria, viruses,
cancer, or other harmful
substances.
LYMPH NODES continued…
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Y. pestis spreads through
the infected human until it
reaches a lymph node,
where it starts to bleed
and swell,
The expansion of lymph
nodes is the cause of the
characteristic "bubo"
(Bubonic) associated with
the disease.
The Plague Life Cycle
Oriental Rat Flea
3 Forms of the Black Plague
1.
BUBONIC
2.
PNEUMIONIC
3.
SEPTICEMIC
BUBONIC PLAGUE
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Fleas transmit the bacteria from animals
(eg, prairie dogs, squirrels, chipmunks,
rats, cats) to humans.
Direct contact, animal bites or exposures to
infected carcasses (eg, coyotes, hares,
rabbits, rodents, marmots, goats) are other
sources.
BUBONIC PLAGUE – images to follow
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The onset of symptoms (after an incubation
period of 4 to 7 days) is sudden and includes,
high fever, headache, development of tender
regional lymph nodes called buboes.
Untreated, bubonic plague can progress to
septicemic and occasionally pneumonic plague in
2 to 6 days, and death is frequent.
The mortality rate of bubonic plague is low when
treated early and is about 50% when untreated.
Cannot be transmitted from person to person.
BUBONIC PLAGUE IMAGES
PNEUMONIC PLAGUE
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Pneumonic plague is a severe bacterial lung
infection.
Can take a primary or secondary form.
The primary form is contracted from inhaling
droplets transmitted from an infected person.
Secondary pneumonic plague is a progression of
bubonic or septicemic plague to the lungs.
PNEUMONIC PLAGUE – images to
follow
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Transmissible from human to human via droplets
in air (cough, sneeze, etc.)
The mortality rate of pneumonic plague is 75
percent, despite appropriate plague treatment.
Pneumonic plague is classified as a Category A
bioterrorism agent because of its ease of
dissemination (spreading out), contagiousness,
and high mortality rate.
PNEUMONIC PLAGUE IMAGES
SEPTICEMIC PLAGUE
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There are primary and secondary forms of
septicemic plague.
The primary lacks the typical bubo.
Secondary septicemic plague occurs when
there is the progression of bubonic to
septicemic plague.
Rarely transmissible human to human.
SEPTICEMIC PLAGUE – images to
follow
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Septicemic plague causes fever, chills,
weakness, abdominal pain, shock, and
bleeding underneath the skin or other
organs… regions such as the fingers, toes,
and nose may become gangrenous, hence
the term “black death.”
The mortality rate for septicemic plague is
50 to 90 percent if left untreated; 15% if
diagnosed and treated early.
SEPTICEMIC PLAGUE IMAGES
Black Plague Doctor
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Notice the extensive
fabric,
Covered face,
Crystal eyes,
Beak-like mask
Does the Black Plague still exist
today?
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In the U.S., 1 to 40 cases reported annually
(avg = 13 cases) by western states, 19711995
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Worldwide, 2861 cases reported by 10
countries to WHO (World Health
Organization) in 1995
Who is at risk?
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In the U.S., persons exposed to rodent fleas, wild
rodents, or other susceptible animals in areas of
western states.
Most cases occur in southwestern states of NM,
AZ, CO, and in CA
Highest rates in Native Americans, especially
Navajos; other risk groups: hunters; veterinarians
and pet owners handling infected cats; campers
or hikers entering areas with outbreaks of animal
plague
United States Distribution
Where in the world…?