Pathogen and Host Flashcards
What are the three ways a virus can affect the normal cell function?
Cell destruction
Change gene expression
Cause immunopathogenic disease
Where do viruses enter the body?
Respiratory system
GI tract
Skin contact
Contact of body fluids
Describe characteristic acute viral infection
Localized reaction
Development of viraemia with spread of infection to surrounding tissues
Describe infection of Influenza A
Virus inhaled
Virus infects epithelial cells of the respiratory track
Destruction of respiratory epithelium
Altered cytokine expression causing fever
How are novel influenza generated?
By antigenic drift and shift
Define antigenic drift
A minor change in the genes of the virus that cause it to be immune to previous antigens
Define antigenic shift
A major change in the viruses genes
Give examples of enteroviruses
Myocarditis
Pancreatitis
Respiratory infections
What occurs when enterovirus infects neuronal tissue?
Paralysis
What is a latent virus?
A virus that does not take full effect in the host immediately on infection
What is an example of a latent virus infection?
Herpes simplex
Give examples of virus induced tumors
Cervical carcinoma - papillomaviruses
Lymphoma - Retrovirus
Describe the cycle of a retrovirus
Attachment to cell Membranes fuse Uncoating Viral RNA integrates with host DNA New viral DNA synthesis new virus
Describe the process of retrovirus induced tumour
virus infects cell
virus nucleic acid, as DNA integrates into cellular genome
virus causes changes in cellular gene expression
uncontrolled cell multiplication and tumour formation
