Flashcards in Chapter 36- Influenza Deck (14):
The 4 characteristics of the virus
Segmented, negative sense enveloped single stranded RNA
The two envelope spikes
Hemagglutinin (HA) & Neuraminidase (NA)
Binds to silica acid on epithelial cells. fusion of the envelope.
Cleaves sialic acid
Influenza A is named by:
place of isolation, date of isolation, antigen (HA & NA), and epidemics and pandemics
Influenza B named by
type, geography, date, sometimes epidemics
Influenza C named by
mild respiratory illness, no epidemics
minor mutations that lead to small changes that make the previous immune response less effective.
More dramatic changes. occur less often
Influenza A diversity
Antigenic shift can occur because the virus can infect many animal species.
Local and systemic effects of Influenza A
Local: due to cell changed (mucus secretions; epithelial damage)
Systemic: due to immune response (interferon)
Rapid Ag testing- nasopharyngeal specimen usually the best.
How do neuraminidase inhibitors work?
block the function of viral neuraminidases of influenza by preventing it from budding from the cell.