M4

Question 1

how do pathogens invade a host?

Answer 1

1. adhere/colonize and invade
2. evade host defences
3. multiply/complete its life cycle
4. exit the host

Question 2

what is a natural transmission/spread?

Answer 2

shedding/sneezing

Question 3

what is an artificial transmission/spread?

Answer 3

aerosols, blood, saliva

Question 4

what is a direct spread to a new host (contamination)?

Answer 4

vertical or horizontal

Question 5

what is an indirect spread to a new host ?

Answer 5

formite

Question 6

define exogenous

Answer 6

infective material dervied from outside patients body

Question 7

define endogenous

Answer 7

• bacteria/fungi part of natural microbiota
• Endogenous
  bacteria/ fungi part of natural microbiota
  misplaced, transfer from non-sterile to normally sterile state egS.. sanguinins mouth to blood to heart and endocarditis

Question 8

How can exogenous become infective to the host?

Answer 8

damage to epithelium –> presence of foreign body –> transfer of bacteria to incorrect site –> suppression of immune system –> infection by exogenous pathogen –> disruption of microflora by antibiotics

Question 9

which microorganisms are associated with burns/wounds?

Answer 9

Staphylococcus aureus

Question 10

what are the 3 main factors in establishing disease?

Answer 10

1. dose of infective agent
2. virulence of organisms
3. resistance of host

Question 11

describe the main methods of transmission?

Answer 11

direct - patient to dentist, skin to skin

indirect - cuts burns tooth extraction

Question 12

which microbes are more likely to poise a threat?

Answer 12

endogenous microbe adapted to host and adhered