Viral Pathogenesis Flashcards
1
Q
What are barriers to infection in the respiratory tract?
A
Mucus, cilia, alveolar macrophages, temperature gradient, IgA
2
Q
What are barriers to infection in the respiratory tract?
A
Mucus, cilia, alveolar macrophages, temperature gradient, IgA
3
Q
What droplet sizes get deposited where in the respiratory tract?
A
> 10 micrometres = nose
5-10 micrometres = airways
4
Q
What viruses remain localised and which spread systemically in the respiratory tract?
A
Localised:
- rhinovirus
- respiratory syncytial virus
- influenza virus
Spreading systemically:
- mumps, measles
- rubella virus
- varicella-zoster virus
5
Q
What are barriers to infection in the alimentary tract?
A
- Sequestration in intestinal contents
- Mucus
- Stomach acidity
- Intestinal alkalinity
- Proteolytic enzymes secreted by the pancreas
- Lipolytic activity of bile
- IgA
- Scavenging macrophages
6
Q
What is viremia?
A
Viruses in the blood stream
- can be free in plasma
- -> primary until the liver and spleen - multiplication, becomes secondary
- or cell-associated (within monocytes etc)
7
Q
What are the determinants of tropism?
A
- Availability of receptors for the virus
- Optimal temperature for replication
- Stability in extremes of pH
- Ability to replicated in macrophages and lymphocytes
- Polarized release (apical release less likely to infect deeper layers)
- Presence of “activating” enzymes
