Test 2: Virulence and pathogenesis

Question 1

What is virulence directly related to?

Answer 1

invasiveness and and toxigenic potential

Question 2

How do you measure virulence?

Answer 2

LD50 and ID50 (infectious dose)

Question 3

Endemic

Answer 3

constantly present with low incidence/prevalence

Question 4

Epidemic

Answer 4

new cases of a disease in a certain time period exceed what is expected

Question 5

Pandemic

Answer 5

not limited to one area

Question 6

Progression of infectious disease

Answer 6

• incubation period
• prodromal period
• acute specific illness
• recovery period

Question 7

Adherence to host surface of bacteria (biofilm)

Answer 7

• protection
• degradation
• resistance
• pH
• Gene expression

Question 8

Bacterial invasiveness

Answer 8

• enzymes against body
• capsule
• cell wall proteins
• inflammation

Question 9

Types of inflammation

Answer 9

Pyogenic: fever, pus, fluid
granulmatous: aggregate of cells forming granuloma

Question 10

Endotoxins

Answer 10

not active by themselves, part of gram negative cell walls

Question 11

Exotoxins

Answer 11

secreted by gram positive and negative

Question 12

Exotoxins: neurotoxins

Answer 12

tetanus, diptheria, botulinum

Question 13

Exotoxins: enterotoxins

Answer 13

E. Coli

Question 14

Mechanisms of viral spreading

Answer 14

• Direct local
• lymphatic
• viraemic
• CNS spread (centripital or centrifugal)

Question 15

Viral effect on host cells

Answer 15

• Permissive:allows virus to enter cell and change DNA
• non permissive
• cytopathic

Question 16

Non-permissive infections

Answer 16

• latent: incubated, no symptoms, can be activated by stress
• chronic: virus tries to mutate DNA
• oncogenic
• slow

Question 17

Cytopathic effects

Answer 17

Hemadsorption: clumping of RBCs

Giant cells: abnormal cell division of epidermal cells

Question 18

What is the fungus that has virulent attributes of bacteria?

Answer 18

Aflatoxin