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Flashcards in Natural History of Infection Deck (36)
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1
Q

What is an endogenous infection?

A

An infection caused by an infectious agent already in the body, but has previously been latent or dormant

2
Q

What is an exogenous infection?

A

An infection resulting from invasion and multiplication of pathogenic microorganisms in a bodily part or tissue

3
Q

Where is an endotoxin found?

A

On Gram-negative bacteria

4
Q

What is an endotoxin?

A

The lipopolysaccharide on the outer membrane that can cause disease and produce an inflammatory response

5
Q

What is an exotoxi?

A

A toxin secreted from the micro-organism which disrupts cellular mechanisms

6
Q

What is a superantigen?

A

One that directly stimulates CD4+ T cells

7
Q

What do superantigens cause?

A

A massive inflammatory response

8
Q

What is the reservoir?

A

The natural habitat for the organism in which it can propagate

9
Q

What is the immediate source?

A

Habitat from which the organism is transmitted and which it must survive.

Location of organism between reservoir and susceptible host

10
Q

What happens once an organism has passed from the immediate source to the susceptible host?

A

Multiplication of the organism, and associated damage

11
Q

What viral syndromes are common?

A
  • Viral respiratory infection
  • Viral childhood exathems (rashes)
  • Viral gastroenteritis
  • Viral hepatitis
  • Human papillomavirus
  • Herpesvirdae
12
Q

Give 3 examples of childhood exathems

A
  • Measles
  • Chickenpox
  • Rubella
13
Q

What is the most common cause of viral gastroenteritis?

A

Rotavirus

14
Q

What are some less common causes of viral gastroenteritis?

A
  • Adenovirus
  • Norwalk virus
  • Astrovirus
15
Q

What are the types of viral hepatitis?

A
  • Enteric
  • Blood or body fluid
16
Q

What type of hepatitis is enteric?

A

Hep A

17
Q

What types of hepatitis are blood or body fluid related?

A

B, C and D

18
Q

What does human papillomavirus cause?

A
  • Cutaneous anogenital warts
  • Oncogenic role in development of cervical cancer
19
Q

What are the herpresvirdae?

A

Ubiquitous family that give rise to persistent latent infections that can be reactivated years later

20
Q

What are the main patterns of disease seen in bacterial and viral infections?

A
  • Toxin mediated
  • Acute pyogenic infections
  • Sub-acute infection
  • Chronic granulomatous infections
21
Q

What is the simplest method of disease?

A

Toxin mediated

22
Q

How can a toxin mediated disease be reproduced?

A

Administration of the toxin alone

23
Q

Why can administration of the toxin alone be clinically advantageous?

A

Adaptive immunity can produce anti-toxin antibodies against the infection

24
Q

Where is the pathology often with toxin mediated infections?

A

Distant from the site of bacterial growth

25
Q

Give two common examples of toxin mediated infections?

A
  • Corynebacterium Diptheriae
  • Vibrio Cholera
26
Q

How does the cholera toxin work?

A

Stimulating adenylyl cyclase within the cell, which results in water lost into the lumen of the bowel, causing severe dehydration

27
Q

What happens in acute pyogenic infections?

A

Organisms have rapid disease development spread, and they interact with the immune system to produce an acute inflammatory response

28
Q

What is there a chance of with acute pyogenic infections?

A

Post-infective immune damage

29
Q

Give 2 common examples of acute pyogenic infections

A
  • Staphylococcus aureus
  • Streptococcus pyogenes
30
Q

What are the features of sub-acute infection?

A
  • No pattern to growth rate
  • Any immunopathology may be parallel to direct effects of organism
31
Q

Give an example of a sub-acute infection?

A

Subacute bacterial endocarditis

32
Q

What happens in chronic granulomatous infection?

A

Bacterial growth is slow and organisms often survive and grow intracellularly

33
Q

What are the main examples of chronic granulomatous infections?

A
  • TB
  • Leprosy
34
Q

What is food poisoning characterised by?

A

Diarrhoea with or without vomiting

35
Q

What causes food poisoning?

A

Food-bourne micro-organisms

Numerous causes

36
Q

What patterns of disease does food poisoning mainly fall into?

A

Toxin-mediated or acute