Lecture 5

Question 1

Explain the terms Clinical infection, Subclinical infection and Iatrogenic infection

Answer 1

Clinical infections have symptoms
Subclinical dont have symptoms
Iatrogenic is obtained through a medical practitioner / intervention (hospital)

Question 2

How are respiratory infections transmitted?

Answer 2

Sneeze or salivary transfer from person to person

Question 3

Explain the terms: Endemic, Epidemic, Pandemic and Sporadic.

Answer 3

Endemic is present in a community all the time
Epidemic is wide spread in a community but only occasionally present
Pandemic is wide spread epidemic, not localised to one community (more than one continent)
Sporadic is wide spread, occurring singularly, irregularly or infrequently

Question 4

What is “Epidemiology”?

Answer 4

Epidemiology is the study of the spread, frequency and distribution of diseases.

Question 5

Explain the difference between Morbidity and Mortality

Answer 5

Morbidity is the number made ill by the infective agent

Mortality is the number of deaths cased by the infective agent

Question 6

Explain the difference between Incidence and Prevalence

Answer 6

Incidence is the number of cases over a specific period

Prevalence is the number of cases at a given time

Question 7

In epidemiological terms how would you classify the disease “AIDS”.

Answer 7

Pandemic

Sexually transmitted infection

Question 8

What factors influence the spread of disease in a community?

Answer 8

Virulence of the pathogen
Pathogen transmission mode
Population susceptibility

Question 9

List four ways of preventing the spread of disease in a community.

Answer 9

Immunization
Prevent contamination of water supplies
Proper treatment of water supplies
Proper sewage treatment and disposal

Question 10

Which disease of the following disease types would most likely spread
quickly through the Perth community and why?
A) Gastroenteritis, B) A sexually transmitted disease, C) Influenza

Answer 10

Influenza because of its transmission mode being airborne, it has the most common way of transmission.

Question 11

What are the two branches of the immune system?

Answer 11

The innate and the adaptive branches.

Question 12

How does skin protect against bacteria?

Answer 12

The skin acts as a mechanical barrier to stop foreign invaders from coming in

Question 13

What white blood cells (WBC) types are phagocytic?

Answer 13

Neutrophils, monocytes and eosinophils.

Basophils

Question 14

What type of white blood cell (WBC) is mainly involved in the adaptive immune system?

Answer 14

T cells and B cells

Question 15

What antibody types are involved in the primary and secondary immune response?

Answer 15

IgM and IgG types

Question 16

What type of lymphocyte is involved in cell mediated immunity?

Answer 16

Tc cells

Question 17

List the ways antibodies fight infection.

Answer 17

Agglutination
Neutralization
Opsonization

Question 18

List the antibody isotypes .

Answer 18

IgG
	IgM
	IgA (monomer) Secretory IgA (dimer)
	IgE
IgD

Question 19

What are the 4 cardinal signs of inflammation and how do they come about?

Answer 19

Redness
Heat
Swelling
Pain

Question 20

Describe the difference between humoral and cell mediated immune responses.

Answer 20

Humoral is antibody mediated
Against extracellular invaders
Produced by B lymphocytes

Cell mediated is directly or indirectly killed by lymphocytes
Acts against intracellular invaders Cytotoxic T cells (Tc)

Question 21

List and describe the types of T cells.

Answer 21

T Helper cells

	- Detect antigen on antigen presenting cells
	- Activate macrophages, Tc and B cells
	- Stimulates Adaptive immune response

T Reg cells
-Suppress the immune response

Tc Cells
-Cytotoxic T cells that kill virus infected cells and cancer cells.

Question 22

Describe the difference between passive and active vaccination.

Answer 22

Passive
		Relies on administration of antibodies
		Often after infection or toxin
		Recipient does not produce an immune response of their own
		Short term
	Active
		Administration of antigen
		Prophylaxis (prevent future infection)
		The recipient mounts a response producing own antibodies and memory
		Long term

Question 23

How do autoimmune diseases occur?

Answer 23

When the auto immune system attacks itself. The microbe has a similar antigen to the hosts antigens. Or T cells and antibodies made against the microbe cross react with the host.

Question 24

Give two reasons for preventing microbes from getting into food.

Answer 24

Prevent food related illness

Prevent food spoilage

Question 25

How could microbes contaminate food?

Answer 25

Microbial growth and spoilage

Question 26

How does fermentation preserve food?

Answer 26

Creates an acidic environment where microbes struggle to grow

Question 27

List two of each pathogens that cause illness through food or water?

Answer 27

Gardia lamblia
Norovirus
Rotavirus

Question 28

Why does spoilage of food appear rapid when the microbes are on the food for long periods before the appearance of spoilage?

Answer 28

Due to exponential growth pattern microbes

Question 29

List two reasons for treating waste water.

Answer 29

Removal of pathogens

Prevent contamination with drinking water

Question 30

What is B.O.D?

Answer 30

Biochemical oxygen demand

Question 31

What does BOD indicate?

Answer 31

The amount of organic material present in water

Question 32

What is the main process in secondary sewage treatment?

Answer 32

Microbial digestion of organic material

Question 33

Give 3 uses for Bacteriophage.

Answer 33

Treating bacterial infections
Identify pathogenic bacteria
Recombinant DNA technology