Chapter 36- Influenza

Question 1

The 4 characteristics of the virus

Answer 1

Segmented, negative sense enveloped single stranded RNA

Question 2

The two envelope spikes

Answer 2

Hemagglutinin (HA) & Neuraminidase (NA)

Question 3

Hemagglutinin (HA)

Answer 3

Binds to silica acid on epithelial cells. fusion of the envelope.

Question 4

Neuraminidase (NA)

Answer 4

Cleaves sialic acid

Question 5

Influenza A is named by:

Answer 5

place of isolation, date of isolation, antigen (HA & NA), and epidemics and pandemics

Question 6

Influenza B named by

Answer 6

type, geography, date, sometimes epidemics

Question 7

Influenza C named by

Answer 7

mild respiratory illness, no epidemics

Question 8

Antigenic drift

Answer 8

minor mutations that lead to small changes that make the previous immune response less effective.

Question 9

Antigenic shift

Answer 9

More dramatic changes. occur less often

Question 10

Influenza A diversity

Answer 10

Antigenic shift can occur because the virus can infect many animal species.

Question 11

Local and systemic effects of Influenza A

Answer 11

Local: due to cell changed (mucus secretions; epithelial damage)
Systemic: due to immune response (interferon)

Question 12

Diagnosis

Answer 12

Rapid Ag testing- nasopharyngeal specimen usually the best.

Question 13

How do neuraminidase inhibitors work?

Answer 13

block the function of viral neuraminidases of influenza by preventing it from budding from the cell.

Question 14

The three types of vaccines

Answer 14

1) Inactivated- 3 to 4 inactivated influenza vaccine. grown in egg, purified and inactivated with formalin
2) Live, attenuated intranasal- cold adapted
3) Recombinant- recombinant and egg free