Unit 9 - Infection

Question 1

What are prions?

Answer 1

Misfolded proteins
Normal prions become abnormal and clump in the brain, acuse damage

Question 2

What are viroids?

Answer 2

Free RNA molecules

Question 3

What are endogenous acquired infections?

Answer 3

Caused by microbiome (on or in us)

Question 4

What is exogenous acquired infection?

Answer 4

Bacteria in the environment

Question 5

What are commensals?

Answer 5

Presence, growth and multiplication of a microorganism that doesn’t interact with host
Rare to cause disease

Question 6

What are opportunistic infections?

Answer 6

Caused by microorganisms commonly found in environment or flora without harm. Causes infections when defenses are compromised

Question 7

What is an apparent infection?

Answer 7

Infection that produces symptoms

Question 8

What is an acute apparent infection? example

Answer 8

<4 weeks with rapid onset
Influenza

Question 9

What is a subacute apparent infection? example

Answer 9

4-12 weeks slower onset
endocarditis

Question 10

What is a chronic apparent infection? example

Answer 10

> 12 weeks long duration
tuberculosis

Question 11

What is a recurrent apparent infection? example

Answer 11

encountered regularly
UTI, thrush, bronchitis

Question 12

What is a local apparent infection? example

Answer 12

affect one body part/area
tonsilitis

Question 13

What is a systematic infection? example

Answer 13

affect entire body
sepsis

Question 14

How does the pathogen come to interact with the host?

Answer 14

Pathogen leave body of infected person
Enter body of susceptible person
Transmission: contact, respiratory, food, waterbourne, faecal-oral, sexual, vertical
Spread: prolif locally, invade, trasnport by blood, nerves, lymph
Infection: overcome defences if compromised or virulence factors

Question 15

What are mechanisms by which pathogens exploit host and damage?

Question 16

What is the chain of infection?

Answer 16

Infectious agent
Reservoirs
Portals of exit
Modes of transmission
Portals of entry
Susceptible host

Question 17

How may the chain of infection be broken?

Question 18

What are the stages of infection?

Question 19

What is incubation period?

Answer 19

Time interval between contact with an infectious agent and appearance of the first symptom of disease

Question 20

What is the infectious period?

Answer 20

Time when infectious agent can be transferred directly or indirectly person-person, animal-human etc

Question 21

What is latent period?

Answer 21

Period between exposure and onset of infectious period
Can be shorter or longer than incubation period

Question 22

Where is normal flora present in the body?

Answer 22

Skin
Upper respiratory tract
Oral cavity
Intestine, esp large
Vaginal tract

Question 23

Where is there an absence of normal flora?

Answer 23

Lower resp tract
Muscle tissue
Blood, tissue fluid
Cerebrospinal fluid
Perioneum
Pericardium
Meninges

Question 24

What is the benefit of the normal microbiome?

Answer 24

Nutrient production and processing
Competition with pathogenic microbes
Digestion of soluble fibre
Harvesting energy by producing short chain fatty acids
Produce enzymes the body doesn’t

Question 25

What is symbiosis and the three types?

Answer 25

Interaction between two different species that are in close proximity for an extended period of time
Mutualism - both species benefit
Commensalism - one species benefits, one is neither helped nor harmed
Parasitism - one species benefits, other is harmed