Lecture 4: Malaria and Plague

Question 1

Flu is the most dangerous type of organism why?

Answer 1

we can have a flu that affects birds but it can mutate and humans can get it

Question 2

what is vaccine acquired polio?

Answer 2

get vaccine and acquired polio from it

Question 3

What is Jared Diamonds hypothesis?

Answer 3

hypothesis based on geo and food
- if ppl grew food other ppl could become engineers etc. allows pop. to advance
- led to segregation of pop

Question 4

why was the initial smallpox vaccine so effective?

Answer 4

cowpox virus that was injected into body

• when we get vaccinated our immune system responds to whole organism
• naturally infected is better than vaccinated

Question 5

Where did malaria originate from?

Answer 5

Believed to have originated among African primates

Question 6

How is malaria transmitted?

Answer 6

Genus Plasmodium, transmitted via female mosquito (anopheles)

Question 7

P. Vivax

Answer 7

infects young erythrocytes

Question 8

P. Malariae

Answer 8

infects mature erythrocytes

Question 9

P. Falciparum

Answer 9

infects both types of erythrocytes (most common in sub-Saharan Africa)

Question 10

P. Knowlesi

Answer 10

infects both types (most common in Southeast Asia

Question 11

Are erythrocytes acellular?

Answer 11

NO
- no nucleus or organelles

Question 12

List the symptoms of malaria

Answer 12

Infection gives you a characteristic fever cycle.

◦ 2-3 days you have increased temperature 40 C - 42 C; not optimal temp regulated by hypothalamus

◦ The fever cycle occurs with a burst of Plasmodium from erythrocytes

◦ This is due to inflammation from the clean up of broken cells

Question 13

Malaria and Immunity

Answer 13

• Innate immunity holds down the parasite count
• Acquired immunity produces antibodies but only after the person has survived
  several attacks
  ◦ Only works on the strain causing the infection

Question 14

Who is immune to malaria and HOW?

Answer 14

Natural selection (genetic evolution) in malarious regions has gradually supplemented acquired immunities by evolving innate resistances

• This is known as Sickle Cell Anemia
• we have evolved to create erythrocytes which couldn’t be infected by malaria

Question 15

Individuals whose origins are in Africa (sub saharan african) may have acquired a genetic trait which protects them from…?

Answer 15

***Plasmodium vivax *

1/4 of the population has this genetic trait.

Question 16

Explain the Plasmodium Vivax transmission?

Answer 16

If two people mate and pass on the sickle cell trait, the resulting offispring will have S.C.Anemia

Question 17

sickle cell anemia

Answer 17

trait which causes the erythrocytes to turn sickle in shape
- prevents plasmodium from entering

Question 18

How fatal is malaria?

Answer 18

• About 1.5 million to 3 million people die every year (85% of these occur in Africa),
  accounting for about 4-5% of all fatalities in the world
• One child dies of malaria somewhere in Africa every 20 sec, and there is one malarial
  death every 12 sec, somewhere in the world.
• Malaria kills in 1 year what AIDS killed in 15 years. In 15 years, if 5 million have
  died of AIDS, 50 million have died of malaria.

Question 19

Why does HIV get so much funding and malaria does not?

Answer 19

malaria doesnt affect western society only Asian and African which ppl dont care abt

• Estimated worldwide expenditure per malaria fatality: $ 65, as compared to $ 3274 for HIV/AIDS and $ 789 for asthma. That is to say, one HIV/AIDS death is equal to about 50 malaria deaths.

Answer 20

Malaria ranks third among the major infectious diseases in causing deaths after
pneumococcal acute respiratory infections and tuberculosis. It is expected that by the turn of the century, would be the number one infectious killer disease in the world.
* Every year - 30,000 visitors to endemic areas develop malaria and 1% of them may die
* Estimated worldwide expenditure on malaria research: US $ 58 million, one thousandth of the US $ 56 billion spent globally on health research annually

Question 21

Describe where malaria vector species are prevelant in the world

Answer 21

As observed malaria strains are prevalent across the world, however methods of treatment and prevention are not globally applicable. What might work in Europe and Asia might not work in sub-Saharan Africa.

Question 22

vaccine equity

Answer 22

impossible to vaccinate everyone b/c impossible to transport vaccine that require -80 degrees celcius temp for ex

Question 23

Where are malaria death rates the highest?

Answer 23

As observed majority of malaria related deaths are prevalent in African countries.

Question 24

What is the general rule of thumb with diseases?

Answer 24

◦ Those who live in close proximity to a particular pathogen for long enough, develop an ability to live with the disease.

we see this with malaria; virus wants to live with you not kill you if it kills host it cannot survive either

• homeostatic relationship: pop. to large virus comes and decreases pop

Question 25

Why does it not make sesne when on the news we hear “new varaiant is more deadly” ?

Answer 25

we have not seen a virus that has increased in pathogenictity in a pop.

Question 26

What are the diseases that are difficult to live with?

Answer 26

Plague, small pox, mumps, Ebola

• b/c virus evolves with pop if they weree to kill everyone virus can’t live anymore

Question 27

When did new plagues hit socities?

Answer 27

New plagues first hit humankind around 3000 BC. when cities over 50,000 were sprung up in Mesopotamia, Egypt, and Indus Valley

Question 28

What happened in 500 BC?

Answer 28

is when pathogens had an impact on the growth of civilization in Asia and Europe.

• Generally these diseases would pass from human to human very quickly and need no intermediary carrier
• These new pathogens changed the course of human history

**One’s people disease became another people’s plague **

Question 29

How did the spread of disease help the population?

Answer 29

disease outbreaks would control population growth

• Which made possible, the food surpluses that sped the development of cities -
  because there was food, people didn’t all need to farm, people could study and
  develop other careers - truths to Diamond’s hypothesis
• Relatively recently, cities were so unhealthy that population could not replace themselves.

Question 30

What were the sociteal impacts of the plague?

Answer 30

was responsible for mass human death, socioeconomic changes, and religious turnovers

plague= rodent disease

Question 31

Where was the 1st documented outbreak of plague?

Answer 31

The first documented outbreak of the plague was in the Roman Empire ◦ Called the plague of Justinian
◦ Lost 1/4 of their population
◦ Devastated Constantinople in 542 AD
◦ Travelled to Mediterranean for two centuries

Question 32

Has the plague been eradicated?

Answer 32

No still present today
- in london they get abt 100 cases every year

Question 33

The Black Death

When did it begin? where

Answer 33

Second cycle of plague

◦ Greatest imprint on the population

Began in 1300 and ended in 1800

◦ Began in Asia and swept through Middle East, North Africa, and Europe

Question 34

How did the Black death affect the population?

Answer 34

Europe alone lost over 20 million people

◦ Between 20% and 60% and higher died in cities

◦ Often forcing people to abandon their towns and villages for none infected areas
(this changed the socioeconomic of the cities)
- the upperclass would abandon the cities and go to their homes in the country leaving the poor on their own. People left in cities would occupy power positions that were left vacant.

Question 35

What is the genus

Answer 35

Yersinia pestis

‣ Human and animal disease

Question 36

List the 2 types of plague infections

which is more deadly

Answer 36

‣ Bubonicplague
‣ Pneumonic plague - much worse

Question 37

Reservoir

Answer 37

Arthropod reservoir

Question 38

How was plague transmitted?

Answer 38

◦ Bitten by rodent/flea that is carrying the plague bacterium

◦ Handling an infected animal ‘flea transmission’

Fleas become infected by feeding on rodents, such as chipmunks, prairie dogs, ground squirrels, mice, and other mammals that are infected with the bacterium Yersinia pestis. Fleas transmit the plague bacteria to humans and other mammals when it comes and bites you

Question 39

Period of communicability

Answer 39

Susceptibility among the unvaccinated is universal

vaccine was actually not needed there were other ways to gte rid of the

Question 40

Bubonic Plague

Answer 40

Infection of the lymph system

Signs occur 2 to 6 days after being infected

No person to person transmission

When plague is left untreated, plague bacteria invade the bloodstream
- Causes septicaemia

Lives in phagocytes cells which accumulate in the lymph nodes.

Question 41

septicaemia

Answer 41

infection of the blood

Question 42

If the bubonic plague is living in phagocytic cells what does that mean?

Answer 42

if its infecting phagocutic cells its hiding from immune system similar to HIV

phagocytyes; part of immune response

Question 43

Pneumonic plague

Answer 43

infection of the lungs causes the pneumonic plague

sever respiratory illness with, high fever, chills, cough, and breathing difficulty with expel bloody sputum

• Person to person transmission
• There is also swollen lymph nodes
• Without antibiotic therapy, the disease can progress rapidly to death

Question 44

What is bloody septum a symptom of?

Answer 44

cancer plague TB

Question 45

What are the signs and symtpons of Plague?

Answer 45

• Most common form of human plague is a swollen and very tender lymph gland, accompanied by pain.
• Swollen gland is called a “bubo” (hence the term ‘bubonic plague’)

Question 46

When should you suspect someone has the plague?

Answer 46

when a person develops a swollen gland, fever,
chills, headache and extreme exhaustion, and has a history of possible exposure to infected rodents, rabbits or fleas