2. Basic information
The plague is a serious bacterial infection that can be deadly. Sometimes referred to as the
"black death," the disease is caused by bacteria called Yersinia pestis. This bacteria is
found on animals throughout the world and is usually transmitted to humans through fleas.
Domain:Bacteria Kingdom:Eubacteria Phylum: Proteobacteria Class:Gammaproteobacteria
Order:Enterobacteriales Family:Enterobacteriaceae Genus:Yersinia Species:Y. pestis
The bacteria is Gram negative coccobacillus. It can be detected in blood, fluid in buboes.It is
stained using Giemsa, Wright, Wayson's stain - Bipolar safety pin staining.
In medieval times, the plague, or "black death," was responsible for the deaths of millions of
people in Europe. Today, there are only 1,000 to 3,000 cases reported worldwide each year,
with the highest incidence in Africa.
Plague is a rapidly progressing disease that can lead to death. Immediate medical
intervention is necessary.
3. The History
The three main pandemics
• The Justinian plague
:541 AD Meditarranean
basin.
• Black death or the Great
plague : China 1334
• Modern plague : China
1894
4.
5. How it spreads ?
People usually get plague through
the bite of fleas that have previously
fed on infected animals like mice,
rats, rabbits, squirrels, chipmunks,
and prairie dogs. It can also be
spread through direct contact with
an infected person or animal, or by
eating an infected animal. According
to the National Institutes of health,
plague can also spread through
scratches or bites of infected
domestic cats
It is rare for bubonic plague or
septicemic plague to spread from
one human to another.
6. Bubonic type:
Bubonic plague is the most common variety of the disease. It's named after the buboes — swollen
lymph nodes — which typically develop within a week after an infected flea bites you. Buboes may be:
Situated in the groin, armpit or neck
About the size of a chicken egg
Tender and warm to the touch
Other signs and symptoms may include:
Sudden onset of fever and chills
Headache
Fatigue or malaise
Muscle aches
8. Pneumonic type:
Pneumonic plague affects the lungs. It's the least common variety of plague but the most dangerous,
because it can be spread from person to person via cough droplets. Signs and symptoms can begin
within a few hours after infection, and may include:
Cough, with bloody sputum
Difficulty breathing
High fever
Nausea and vomiting
Weakness
Pneumonic plague progresses rapidly and may cause respiratory failure and shock within two days of
infection. If antibiotic treatment isn't initiated within a day after signs and symptoms first appear, the
infection is likely to be fatal.
10. Septicemic type :
Septicemic plague occurs when plague bacteria multiply in your bloodstream. Signs and symptoms
include:
Fever and chills
Abdominal pain, diarrhea and vomiting
Bleeding from your mouth, nose or rectum, or under your skin
Shock
Blackening and death of tissue (gangrene) in your extremities, most commonly your fingers, toes and
nose
14. Prevention
• Keeping the rodent population under control can greatly
reduce your risk of getting the bacteria that causes plague.
• Keep your home free from stacks of firewood or piles of
rock, brush, or other debris. Don’t leave pet food out and
protect your pets from fleas. Use insect repellent products
or natural insect repellants like citronella when spending
time outdoors.
• If you have been exposed to fleas during a plague
outbreak, visit your doctor immediately so your concerns
can be addressed quickly.
• A vaccine is available,It consists of killed y.pestis
but is only recommended as a preventative measure for
high-risk groups (like laboratory staff). According to the
World Health Organization, the vaccination is not a proven
method of preventing plague during an outbreak (WHO).
15. Facts about plague
The term "Black Death" is recent. During the plague, it was called "the Great Mortality" or "the Pestilence."i
The first named victims of the plague died in 1338 and 1339 in the area around Lake Issyk Kul (Lake Baikal) in
Russia, where a grave marker says, "In the year of the hare (1339). This is the grave of Kutluk. He died of the
plague with his wife, Magnu-Kelka."c
A November 2000 study of tooth pulp in a French plague grave showed the presence of Y. pestis in all of 20
samples from three victims.c
Y. Pestis infects its flea by blocking its stomach. The flea tries repeatedly to feed, but the blockage causes it to
regurgitate bacilli into its host. When the host dies, the flea and its offspring seek a new host, infesting humans
when necessary.a
The mortality rate for humans who caught the bubonic plague was 30-75%. The pneumonic plague killed 90-
95% of its victims. The septicemic plague killed nearly 100% of the people it infected and still has no cure to this
day.
16. “
”
Let food be thy medicine and
medicine be thy food
-- HIPPOCRATES
