Week 3 - Influenza 101 Flashcards
What are some opportunities to intervene with influenza?
Vaccines, antivirals, other mitigation activities
What is the strongest predictor of when influenza season is?
Climate
How often does the influenza virus mutate?
Continuously
Pandemic influenza occurs due to ____________ _____________
Antigenic Shift
When is influenza season in a place with a temperate climate?
Winter
What are some risk factors for severe outcomes associated with influenza?
- Age (<6 months, >65 years)
- Chronic medical conditions (Ex. diabetes, HIV/AIDS, asthma, etc.)
- Pregnancy
- Morbid obesity
- Living in a nursing home
When is influenza season in tropical and subtropical climates?
Year-round
How is influenza transmissited?
Contact, Droplet, Airborne.
Droplet is the main form of transmission
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
A. Stainless Steel countertop (influenza likes non-porous surfaces)
Which types of influenza causes the majority of human infections?
Influenza A and Influenza B
What do the H and the N in H1N1 stand for?
H= Hemagglutinin
N= Neuraminidase
What is the function of hemagglutinin?
Allows the flu virus to adhere to the respiratory tract
What is the function of Neuraminidase?
Allows the flu virus to escape from respiratory cells after replication
What is antigenic drift?
The acquisition of point mutations (associated with seasonal epidemics)
What is antigenic shift?
The acquisition of novel genes through reassortment (associated with pandemics)
Which influenza type has a wider host range?
Influenza A
Which influenza type is more likely to cause a pandemic?
Influenza A. Influenza B mutates at a rate 2-3 times lower than type A
Why is influenza a major public health problem?
- 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
What are two ways to prevent influenza exposure?
Personal respiratory hygiene and physical distancing
What are two means to prevent influenza infection?
Vaccines and antiviral prophylaxis
Which strains are currently included in the annual flu vaccine?
A/H3N2, A/H1N1, B/Victoria, B/Yamagata
What are some examples of Influenza pandemics from history?
- 1918 H1N1 Pandemic (Spanish Flu)
- 1957 H2N2 Pandemic
- 1968 H3N2 Pandemic
- 2009 H1N1 Pandemic (Swine Flu)
