Transmission of Infection

Question 1

What are Koch’s Postulates and what do they determine?

Answer 1

Determine if an infectious agent is the cause of a disease

1. Organism occurs in every case of the disease
2. Occurs in no other disease
3. On removal from the body and growing in pure culture, it can induce the disease again

Question 2

What are the recognised sources of infection?

Answer 2

Animal to person 
Meat
Waterborne
Cross-contamination in food prep
Person to person
Other foods of animal origin
Contamination of food with ruminant faeces

Question 3

Describe the components in the transmission of infection

Answer 3

1. Reservoir
2. Immediate source
3. Mode of transmission
4. Susceptible host

Question 4

Name the to main methods of transmission of infections

Answer 4

Exogenous (transmitted from outside the body)

Endogenous (transmitted from inside the body)

Question 5

Give the components included in the formation of microbe-human associations

Answer 5

1. Encounter (microbe comes into contact with human, exogenous transmission)
2. Entry/establishment (human is infected with microbe – it is colonised)
3. Spread (endogenous as spreading from human)4. Multiplication
4. Damage
5. Outcome

Question 6

Give examples of endogenous transmission

Answer 6

FROM THE NORMAL FLORA

• • From a wound
• • Urinary Tract Infection

Question 7

How can you prevent the transmission of infection?

Answer 7

1. Eliminate dangerous microbes
2. Isolate highly susceptible patients from source of infection
3. Protect the susceptible host
4. Remove the mode of transmission