the black plague. the italian writer boccaccio said the plague’s victims often… "ate lunch...
TRANSCRIPT
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 Yersinia pestis
Discovered by Alexandre Yersin, a French bacteriologist in 1894.
LYMPH NODES 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… 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 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
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 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
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 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
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
Notice the extensive fabric,
Covered face, Crystal eyes, Beak-like mask
Does the Black Plague still exist today?
In the U.S., 1 to 40 cases reported annually (avg = 13 cases) by western states, 1971-1995
Worldwide, 2861 cases reported by 10 countries to WHO (World Health Organization) in 1995
Who is at risk? 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…?