Disease Challenges and Strategies

Question 1

How was disease brought about?

Answer 1

> Europeans brought disease such as a wave of epidemic diseases including smallpox, typhoid, pneumonia, whooping cough etc.
Many of the europeans colonist populations had resistance to diseases like measles, scarlet fever as thy already had been exposed to the responsible pathogens before coming to Australia.
However, these diseases spread rapidly through and annihilated those who hadn’t been exposed to it before.

Question 2

Diet?

Answer 2

> There was restricted access to traditional foods, rationing was imposed ( low quality and quantity of foods)
Aboriginal people where forced to adapt to European style of high sugar and flour based diet

Question 3

Lifestyle?

Answer 3

> Nomadic life morphed into a more stationary lifestyle
As Aboriginal people lived in one place = to an increased exposure to an increased spread of pathogens

Question 4

Pathogen

Answer 4

A disease causing organism

Question 5

Infection

Answer 5

Occurs when a pathogen has breached the first line of defence and has started to replicate within the host

Question 6

Disease

Answer 6

Is the consequence of the pathogen’s invasion causing damage and impacting on the normal function of the body’s tissues

Question 7

Virulence

Answer 7

The likelihood that a pathogen, once it is in the body, will cause disease and harm to the host

Question 8

Contagious

Answer 8

Is the likelihood that the pathogen will spread between individuals

Question 9

Emerging Disease

Answer 9

A disease that has occurred in humans before, or has occurred previously, but affected only a small number of people.
E.g. HIV infections, west nile virus, lyme disease, ebola.

Question 10

Re-emerging disease

Answer 10

A disease that was once present and had a dramatic decline in case numbers, but has returned and is affecting a significant proportion of the population.
E.g. Influenza, malaria, tuberculosis.

Question 11

Contributing factors to emergency of disease is human behaviour

Answer 11

> Population growth, travel, poverty, ecological damage, food supply chains, intensive farming and climate change

Question 12

2 reasons for a disease to re-emerge

Answer 12

> Resistance/ Evolution of a pathogen
Drop of vaccination numbers

Question 13

Resistance

Answer 13

Bacteria can either mutate or exchange genetic material with other bacteria of the same or different species.

Question 14

Mutations

Answer 14

Mutations of bacterial genes could result in the bacteria being able to:
> Prevent drugs from adhering to their surface
> Decrease the permeability of their plasma membrane to drugs
> Actively pump out the drug
> Use enzymes that destroy the action of the drug

Question 15

Exchange of Genetic Material

Answer 15

> Conjugation is one way in which genetic material is exchanged between bacteria.
Involves the pilus from one bacterium extending and joining that of another bacterium, forming a bridge enabling the plasmid DNA to be exchanged between the two bacteria.
The plasmid could then contain a gene that increases the bacterium’s ability to survive medications.
The widespread use of antibiotics is acting as a selection pressure driving the evolution of stronger and more resistant pathogens.

Question 16

Differences between endemic, epidemic and pandemic

Answer 16

> Classification due to rate of spread, not severity.
Endemic: Transmission occur, but the number of cases remain constant
Epidemic: The number of cases increases
Pandemic: When the epidemic occur at several continents (global epidemic)

Question 17

Endemic

Answer 17

> Similar to a pandemic due to its contagiousness and longevity
Contained to a specific geographical area
More predictable and therefore easier to manage

Question 18

Epidemic

Answer 18

> An unexpected increase in the number of disease cases in a specific geographical area. Disease in this context doesn’t always pertain to a contagious illness

Question 19

Pandemic

Answer 19

> When the growth rate of a particular disease or sickness is considered exponential.
Spread across many countries

Question 20

Immunotherapy

Answer 20

> Is a treatment for a disease that causes the activation or suppression of the immune system.
The main types of immunotherapy include:
- Monoclonal antibodies (mAbs)
- Non-specific immunotherapies
- Cancer vaccines

Question 21

Monoclonal Antibodies

Answer 21

Are made in the laboratory to work in the same way that naturally produced antibodies respond during the adaptive immune response.
There are numerous types and can be made to target a variety of cells and substances.

Question 22

Two types of mAbs

Answer 22

> Bispecific mAbs: Attach to target cells to signal for an immune response. Is laboratory made with two different antigen-binding sites, so it can attach to two different antigens at one time.

> Conjugated mAbs: Deliver a cytotoxic or radioactive ‘payload’ directly to the target cell. Is one that has been combined with a chemotherapy drug (a cytotoxin) or radioactive substance.
Can therefore be used to deliver the drug or radioactive substance directly to the cancerous cells, preventing their growth and lessening the damage to healthy cells in the area.

Question 23

Autoimmune Disease

Answer 23

> Are a malfunction of the immune system.
Using drugs against the malfunctioning cells is difficult due to the risk of weakening the immune response so much that it allows pathogens to take hold.
Treatments should specifically target only the malfunctioning cells or molecules of the immune system, not the whole system.

Question 24

Multiple Sclerosis

Answer 24

Occurs when a person’s own immune cells attack the central nervous system, resulting in damage to the insulating myelin sheath of nerve cells.

Ocrelizumab is the first approved monoclonal antibody treatment for a type of multiple sclerosis.
Ocrelizumab targets the CD20 receptor of B cells.
Reduced the attacks by the immune cells on the central nervous system.

Question 25

Allergic Reactions

Answer 25

Another example is the use of mAbs to inhibit IgE antibodies involved in moderate to severe allergic reactions.

Question 26

Sources of protein that makes up mAbs

Answer 26

> Murine: Made of mouse proteins
Chimeric: A mixture of mouse and human proteins
Humanised: Mouse Protein attached to predominantly human proteins
Transgenic: Fully human proteins produced with the use of transgenic mice

Question 27

How to make mAbs

Answer 27

> The first mAbs were mouse mAbs.
So not to be rejected by humans (as mouse mAbs would be considered non-self), researchers used recombinant DNA techniques to produce chimeric, humanised and transgenic mAbs.