viruses Flashcards
Describe a viruses size
- 20-300nm
- visualised under electron microscopy
What shapes do viruses usually have?
- icosahedral
- helical
Which characteristic of viruses make it use the host cellular machinery to replicate?
they are obligate intracellular parasites
Describe the capsid of a virus
protein coat that encloses genome and core proteins
Describe the envelope of a virus
- lipid bilayer that surrounds capsid of SOME viruses
- it contains glycoproteins that form projections
Describe the genome of a virus?
- either DNA or RNA
What are the different person-to-person HORIZONTAL transmission routes for viral infections?
- airborne
- fecal-oral
- sexual
- vector-borne
- blood
What is the VERTICAL transmission route for viral infections?
from mother to child
What is pathogenesis?
study of the disease process
What is invasiveness?
the capacity of a virus to enter a tissue or organ
What is tropism ?
ability of different viruses to infect different cell types
What is virulence?
the ability for a virus to cause disease
What are the methods for viral diagnosis?
- direct detection
- indirect detection
Describe direct detection of viruses?
- detection of the whole virus or parts of it
Describe indirect detention of viruses?
- detection of human antibodies against the virus