example of viral diseases prions Flashcards
most prevalent human infections are caused by
viruses
chicken pox is caused by
varicella-zoster virus
characterization of chicken pox
systemic papular rash
when varicella-zoster rises to the skin surface
shingles
rhinovirus
single-stranded RNA virus
influenza is caused by
RNA virus of the orthomyxovirus group
- influenza A is the most important human pathogen
antigenic shift
abrupt, major change in the influenza A virus resulting in new subtype or virus. gene reassortment
antigenic drift
small changes in the genes of influenza virus that happen over time as the virus replicates
HIV causes AIDS
true
HIV pathogenesis
- HIV infects cells that contain the CD4 cell surface protein
- most commonly infected are macrophages and T-helper cells
- HIV also interacts with coreceptors on target cells
HIV infection does not immediately kill the host cell
true
infection with HIV results in a progressive decline in what type of cells
CD4
when CD4 cells decline, ____production falls, leading to a reduction in ___________ ____________
cytokine///immune response
HIV-1
more virulent
HIV-2
less virulent and causes a milder AIDs-like disease