Pathogenesis

Question 1

What is the difference between colonization, infection, and disease?

Answer 1

• Colonization is the presence and persistence of microorganisms in the body and does not necessarily lead to disease
• infection is colonization that leads to disease
• disease is an infectious process that adversely affects the body

Question 2

What is pathogenicity?

Answer 2

The capacity of an organism to cause disease

Question 3

What is virulence?

Answer 3

The degree to which an organism can cause disease ( how severe or how easily ). a virulence factor is a constituent of the agent that promotes infection

Question 4

Which are the steps in pathogenesis?

Answer 4

1 - Encounter (Endogenous - Normal flora; Exogenous - agent in the environment)

2- Entry (Ingress - epithelial barrier not crossed (inhalation, ingestion); Penetration - epithelial barrier is crossed (cut, insect bite, scrape, virulence factor))

3- Spread (movement, dissemination)

4- Multiplication

5- Damage

6- Outcome

Question 5

Which are the factors that affect spread?

Answer 5

• Anatomy (structure)

- Active participation by the microbe (enzymes, flagella, toxins)

Question 6

Is multiplication necessary for all organisms?

Answer 6

No. It is not necessary for highly virulent organisms or those that mediate disease via toxins

Question 7

What is immunopathology?

Answer 7

The host’s response to the agent

Question 8

Which are the possible outcomes in pathogenesis?

Answer 8

Death - Infectious agent wins
Health - host clears infection
Symbiosis - host an organism to learn to coexist persistent/ chronic infection

Question 9

What is the difference between true pathogens and opportunistic pathogens?

Answer 9

True pathogens cause disease even in healthy hosts while opportunistic pathogens cause disease in under compromised or unusual conditions ( flora which in new location )