Historical plagues

Question 1

Historical plagues

Answer 1

Vibrio cholera
yersinia pestis

Question 2

Vibrio Cholera

Answer 2

gram-negative
curved (vibrio) shaped
Flagellum (monotrichous)
in water
Pili throughout the cell surface

Question 3

the disease is known as “Cholera”

Answer 3

After ingestion the majority are killed by gastric acid
Surviving ones colonize small intestine and secrete CT
causes watery diarrhea “rice water stool”

Question 4

History of Cholera

Answer 4

Descriptions of disease found in Sanskrit to the 5th century BC-originated in India
1817 cholera spread beyond Indian subcontient

Question 5

Transmission

Answer 5

Asymptomatic- shed for a few days, without symptoms, accidental pathogen
Symptomatic-Shed between 2 days and 2 weeks, present in human stool, in environmental water

Question 6

Pandemics

Answer 6

7 cholera pandemics in total
3rd-death toll:1 million originated in India and spread west
6th-death toll: 800,000+, originated in India and spread east
7th still ongoing
affects 3-5 million people each year, kills 120,000
Asia and Africa

Question 7

Clinical manifestations

Answer 7

Early illness: vomiting, cramping, fecal matter or bile in stool- up to 1 liter per hour
Late Phase: massive watery diarrhea, characteristic “rice water stool” hypotensive shock, and death
Fever is rare
Dehydration +electrolyte loss: Sunken eyes, dry mouth, cold clammy skin, urine output decreases, etc.

Question 8

Treatment

Answer 8

Rehydration
aggressive fluid replacement
Antibiotics decrease the volume and duration of diarrhea by 50%

Question 9

Prevention

Answer 9

High case fatality rate: population density, lack of sanitation and health infrastructure
prevention depends on access to safe water and sanitation

Question 10

Yersinia pestis

Answer 10

Gram-negative
Coccobacillus
Non-motile

Question 11

History

Answer 11

discovered in 1984, by Alexandre Yersin, Yersin linked plague with a bacillus, initially named Pasteurella pestis was renamed Yersinia pestis in 1944
2010: researchers established that Y. pestis cause of the black death
2011: first genome isolated from black death victims

Question 12

Transmission

Answer 12

Parasite of the rat flea, which is also a parasite of rats
hyperparasite
people can become infected: Bitten or scratched by infected animals, inhale respiratory droplets, eat infected animals

Question 13

Y. pestis pandemics

Answer 13

Justinian plague: 541 to 750/767 CE
Second pandemic: 1346 to the 18th century,Europe +Asia,lack of travel
3rd pandemic: 1772 china, spread worldwide

Question 14

Black death pandemic

Answer 14

from 1346 to 1353
Death toll: 75-200 million
Originated in Asia and through Africa +Europe
Jumped continents-merchant ships-rats lived on

Question 15

Diagnosis

Answer 15

sole disease by swollen lymph nodes referred to as buboes
classic plague doctor: Wide-brimmed hat-Doctor, Bird beak mask- birds carried plagues, Red glass eyepieces-ward off evil spirits, Long black overcoat tucked around mask-wax, wooden cane,leather breeches under overcoat

Question 16

Manifestations

Answer 16

Skin ulceration where bit
reported as carbuncles and ulcers
pustules, spots,petechiae,brusing,gangrene
five main forms: Bubonic, septicemic, pneumonic, meningeal,pharyngeal

Question 17

Bubonic

Answer 17

Most common
Lymph nodes near site of exposure become swollen and extremely painful-armpits,neck, and groin
Fever,headache, chills, fatigue, vomiting,etc.
Antibiotic treatment reduces fatality from 60% to less than 5

Question 18

Septicemic

Answer 18

transmitted directly into the bloodstream-no obvious swollen lymph nodes
cell and tissue death, or necrosis and gangrene- pulls blood from extremities
Fever, chills, malaise, and gastrointestinal symptoms
with no antibiotics, a 30-50% mortality rate

Question 19

Pneumonic

Answer 19

Inhaling bacteria
most uncommon
Flulike illness rapidly to pneumonia
coughing, chest pain, and bloody sputum
high mortality rate, even with treatment-80%

Question 20

Medieval treatment

Answer 20

Divine punishment from God: Repent-brotherhood of the flagellants: town to town, whipping self
Miasma theory: Bad air spreads sickness, foul winds that carried the Plague had risen from oceans in the south
To bring balance: Bloodletting- cutting a vein to drain away blood, barber, specific vein,rich used leeches -“bad blood”