Influenza

Question 1

Explain antigenic shift and drift-

Answer 1

Shift: genetic reassortment for haemaglutinin or neuraminidase via coinfection with pigs, birds etc. No previous immunity
Drift: mutations in HA and NA proteins

Question 2

Risk of death with H1N1 - swine flu

Answer 2

pregnancy
obesity
immunosupression
chronic underlying disease

Question 3

Influenza which viral family?

Answer 3

Orthomyxovirus

ssRNA

Question 4

Which protein is for attachment?

Answer 4

Haemagglutinin

Question 5

How long do you shed the virus?

Answer 5

24-48 hours prior to developement of symptoms, and for 6-8 days after the onset.
Incubation time is about 2 days ususally

Question 6

How do the neuraminidase inhibitors work and what is their effect?

Answer 6

Inhibit the cleavage of the virus from sialic acid–>block release of new virus.

Reduce duration of sx by 1.5 days
Some studies have also shown reduction in antibiotic use and influenza related complications

H1N1 resistant to oseltamivir but STILL sensitive to Zanamavir

Question 7

How effective is the influenza vaccination?

Answer 7

70% for one year

Targets are the haemagluttinins