An introduction to viruses Flashcards
How big are viruses?
20-400nm
Are viruses cellular?
No, they require a host
5 ways virus families are classified
- Virion shape/symmetry
- Presence/ absence of envelope
- Genome
- Mode of replication
- Host range
What are spike projections on the envelope useful for?
Immune system
Explain how the genetic information is arranged in a virus
Nucleic acid with virion associated polymerase surrounded by a protein capsid
Give some examples of how viruses can be transmitted
Blood borne, sexual, vertical ( hep B), faecal oral route, droplet (large particles), airborne, close contact, vector borne, zoonotic ( can lead to generation of new strain)
Does Hep B have immunity?
No
Does measles have immunity?
Yes, long term
Name the 3 broad categories of viral detection
- Whole organism
- Immune response to pathogen
- Part of an organism
Whole organism detection
Is difficult as in a cell but can use microscopy or culture in cells, tissues or animals in agar at 5% CO2
Immune response to pathogen detection
Antibody detection: PCR, acute/recent infection, prior infection/ response to vaccination
Part of an organism detection
- Antigen
- Nucleic acid
- PCR
Are all antiviral agents virustatic or virucidal?
Virustatic
Give some examples of characteristics which could mean there is a potential to eradicate a virus
No animal, no chronic carrier state and political/social support
Respiratory viruses
Influenza A
Rhinovirus
Respiratory syncytial virus
