Week 3 - Influenza 101

Question 1

What are some opportunities to intervene with influenza?

Answer 1

Vaccines, antivirals, other mitigation activities

Question 2

What is the strongest predictor of when influenza season is?

Answer 2

Climate

Question 3

How often does the influenza virus mutate?

Answer 3

Continuously

Question 4

Pandemic influenza occurs due to ____________ _____________

Answer 4

Antigenic Shift

Question 5

When is influenza season in a place with a temperate climate?

Answer 5

Winter

Question 6

What are some risk factors for severe outcomes associated with influenza?

Answer 6

• Age (<6 months, >65 years)
• Chronic medical conditions (Ex. diabetes, HIV/AIDS, asthma, etc.)
• Pregnancy
• Morbid obesity
• Living in a nursing home

Question 7

When is influenza season in tropical and subtropical climates?

Answer 7

Year-round

Question 8

How is influenza transmissited?

Answer 8

Contact, Droplet, Airborne.
Droplet is the main form of transmission

Question 9

With all other conditions being equal, on which of the following surfaces would a flu virus live the longest?
A. Stainless steel countertop
B. Tissue
C. Your hands
D. Cotton handkerchief

Answer 9

A. Stainless Steel countertop (influenza likes non-porous surfaces)

Question 10

Which types of influenza causes the majority of human infections?

Answer 10

Influenza A and Influenza B

Question 11

What do the H and the N in H1N1 stand for?

Answer 11

H= Hemagglutinin
N= Neuraminidase

Question 12

What is the function of hemagglutinin?

Answer 12

Allows the flu virus to adhere to the respiratory tract

Question 13

What is the function of Neuraminidase?

Answer 13

Allows the flu virus to escape from respiratory cells after replication

Question 14

What is antigenic drift?

Answer 14

The acquisition of point mutations (associated with seasonal epidemics)

Question 15

What is antigenic shift?

Answer 15

The acquisition of novel genes through reassortment (associated with pandemics)

Question 16

Which influenza type has a wider host range?

Answer 16

Influenza A

Question 17

Which influenza type is more likely to cause a pandemic?

Answer 17

Influenza A. Influenza B mutates at a rate 2-3 times lower than type A

Question 18

Why is influenza a major public health problem?

Answer 18

• Wide spread annual transmission
• Potential for global pandemics
• Certain groups can develop severe complications
• Substantial economic impact
• Can overwhelm the healthcare system during epidemics and pandemics
• Low risk of severe complication x high incidence= major public health burden

Question 19

What are two ways to prevent influenza exposure?

Answer 19

Personal respiratory hygiene and physical distancing

Question 20

What are two means to prevent influenza infection?

Answer 20

Vaccines and antiviral prophylaxis

Question 21

Which strains are currently included in the annual flu vaccine?

Answer 21

A/H3N2, A/H1N1, B/Victoria, B/Yamagata

Question 22

What are some examples of Influenza pandemics from history?

Answer 22

• 1918 H1N1 Pandemic (Spanish Flu)
• 1957 H2N2 Pandemic
• 1968 H3N2 Pandemic
• 2009 H1N1 Pandemic (Swine Flu)