Test Two: Module 5 The Plague

Question 1

Define zoonotic disease:

Answer 1

disease originated in and transmitted from animals to other animals… in this case… the human animal

Question 2

Define epizootic disease:

Answer 2

Relating to a rapidly spreading disease that affects a large number of animals at the same time within a particular area.

Question 3

Name the etiological agent associated with The Plague:

Answer 3

Yersinia Pestis bacterium

Question 4

Name the three forms of the plague:

Answer 4

bubonic, pneumonic, septacemic

Question 5

What was the vector for the plague and what forms are associated with this vector?

Answer 5

Flea; bubonic, septacemic

Question 6

How was the pneumonic form of the plague spread?

Answer 6

Air-borne water droplets from coughing

Question 7

What is an animal reservoir for the plague?

Answer 7

The animal reservoir for plague includes mice, camels, chipmunks, prairie dogs, rabbits, and squirrels, but the historcially most dangerous for humans are rats,

Question 8

Name the three varieties of Yersinia Pestis:

Answer 8

Orientalis, medievalis, and antiqua

Question 9

What plague pandemic is associated with antiqua?

Answer 9

probably caused the plagues of antiquity, Plague of Justinian 6th-8th century. Still exists around the Great lakes of central Africa.

Question 10

What plague pandemic is associated with medievalis?

Answer 10

Probably caused the Black Death 14th-19th century.

Question 11

What plague pandemic is associated with Orientalis?

Answer 11

Variety that exists most often today, responsible for most recent pandemic of the Far East 19th-20th century

Question 12

How does Yersinia Pestis cause illness(infection)?

Answer 12

1) Produces toxin lethal to host cells
2) When ingested by white blood cells they (bacteria) continue to multiply
3) Progeny disseminate throughout the body
4) Bacilli accumulate in the blood stream and clog capillaries, causing them to burst.
5) Blood filled fluid swells lymph nodes ( causing pain)
6) Secondary infections cause abscesses

Question 13

How does Yersinia Pestis cause death?

Answer 13

1) Cuts off immune cell’s ability to communicate with other immune system cells needed of fight off bacterial invasion
2) Attacks family of molecules used by mammalian cell to transmit signals involved in immune response and cell death

Question 14

How does Yersinia Pestis bypass immune response?

Answer 14

1) Invades directly through skin and engages host macrophages and neutrophils at site of invasion (most Y. pestis killed by neutrophils).
2) Survives in macrophages during early stages of infection ( wax-like structure of the cell wall resists phagocytosis).
3) temperature transition to human host (98.60F) produces non-stimulatory proteins containing CCR5

Question 15

How does the temperature change from flea to host help the bacterium become more virulent?

Answer 15

make bacteria resistant to serum-mediated cellular destruction and inhibits production of pro-inflammatory cytokines

Question 16

What is the effect of Yersinia pestis on the specific cells of the immune system?

Answer 16

1) Produces thick, anti-phagocytic trail as it moves thoughout the body.
2) Causes depletion of natural killer cells
3) paralyzes phagocytes‘ expression of antigen markers; inhibits maturation of dendritic cells and destroys antigen presentation by dendritic cells
4) suppresses T-lymphocyte activation… inhibits ability to produce cytokines (messenger cells)

Question 17

Contrast Sylvatic and Urban Cylcles of the plague:

Answer 17

Sylvatic (forest) and Urban based on different reservoirs…
Sylvatic (wild, forest) cycle:Sylvatic: fraction of the pathogen population’s lifespan spent cycling between wild animals and vectors

“domestic”, or “urban”, cycle, in which the pathogen cycles between vectors and non-wild, urban, or domestic animals;

Question 18

Describe the characteristics of the bubonic form of plague infection:

Answer 18

1) Enters body through the skin, incubation period 2-6 days,
* if untreated death occurs within 5-8 days with a mortality rate of 40-70% (untreated).
2) Lymph node swelling and abscess formation associated with this form.

Question 19

Describe the characteristics of the pneumonic form of the plague:

Answer 19

1) Y. Pestis enters the body through the lungs, 2) if untreated death occurs within 1-3 days of onset, mortality rate among untreated around 100%.
3) Can be contracted from airborne flea feces or airborne victim’s cough droplets.

Question 20

Describe the characteristics of septicemic plague:

Answer 20

1) if untreated, death occurs hours after onset, 2) mortality 100% (untreated), 30-50% treated
3) virtually no incubation period

Question 21

What is the oldest record of a plague type epidemic?

Answer 21

Amulet dating from 800 BCE-612 BCE for warding off plague. Found in the city of Ashur, Neo-Assyrian period

Question 22

What evidence is presented in the Bible of a possible plague?

Answer 22

I Samual 5:6 Philstines stricken with a plague

Question 23

What was the first instance of a widespread plague pandemic?

Answer 23

Justinian Plague; occurred from the Middle East to the Mediterranean basin during the 6th-8th CE killing approximately 50% of the population in these areas

Question 24

What was the second plague pandemic?

Answer 24

The Black Death; (14th – 19th CE) Origin in early 14th C, destroying nearly 40% of the population in Europe

Question 25

What was the third plague pandemic?

Answer 25

: started in approximately 1855 CE in Yunnan Province, China, killed 12,000,000 in India and China, came to United States ~1900 CE
considered on-going until 1959 (antibiotics)

Question 26

What was another name for the Black Death and what were the dates/ mortality rates during its peak years?

Answer 26

Great Mortality; Europe from 1348 through 1351, killing an estimated 25%–60% of Europeans. Some estimates are as high as 2/3 of the population (25 million) (100 million total)

Question 27

How was the Black death spread across Europe?

Answer 27

Beginning in China, the disease was carried along the sea trade routes to India and Italy as well as on the Old Silk road trade route

Question 28

What is believed to be a possible spreader of the plague further West into Europe from Asia besides trade routes?

Answer 28

Ganges Khan invaded Caffa and threw dead (plague ridden) bodies over the walls contaminating the city. Possibly first “biological” warfare

Question 29

Who were the flagellants?

Answer 29

… believed that God was punishing people for sins… self-flagellation… went from town to town (perhaps bring plague with them

Question 30

What other ethnic group was blamed for the plague?

Answer 30

The Jews, many were burned at the stake throughout Europe

Question 31

What are the dates and geographical course of the third pandemic?

Answer 31

1855-1959; Endemic in India until 1859
Spread to Yunnan Province
10,000s Chinese killed
Reaches Port Cities of Hong Gong and Guangzhou 1894
Bombay, Cape Town, San Francisco
Total Deaths ~12- 15 million

Question 32

What are the important facts about the Plague that occurred in the United States?

Answer 32

1) Introduced in 1900 (ships from Asia)
2) Initial epidemic: Chinatown (1900-1904)
3) Second epidemic: Los Angeles (1907-08)
4) Last Urban Plague: Los Angeles (1924-25)
Spread from urban to rural rodents
Entrenched in Rural Areas
Most Cases:
Northern New Mexico, northern Arizona, and southern Colorado
California, southern Oregon, and far western Nevada

Question 33

Where is the plague still endemic today in the United States?

Answer 33

In western states such as Arizona, Nevada, New Mexico

Question 34

What regions of the world are still experiencing relatively high plague cases and have the potential for an increased instance of the Plague?

Answer 34

Central Africa and India due to overcrowding, living in close contact with flea ridden animals and overcrowding.