Influenza Flashcards
Which type of surface protein will we see on influenza virus? (2)
- Hemagglutinin
- Neuraminidase
What type of protein is influenza surface protein?
glycoprotein
What is the purpose of hemagglutinin glycoprotein?
Facilitate cell entry
Describe influenza genome (4)
- (-) RNA
- Helical
- 8 segments
- Enveloped
Which part of influenza facilitates its ability to cell escape?
Neuraminidase glycoprotein
Which part of influenza anchors its glycoprotein?
M-protein
Which type of influenza strain causes both epidemic and pandemic infection?
Type A strain
How could type A strain cause pandemic infection?
Ability to infect other animals besides human
Different between antigentic drift and antigenic shift?
- Antigenic drift = small mutation to RNA over time to confers to the immune response
- Antigenic shift = mixture of two different virus type infecting the same cells –> generating new virus subtype
Which type of genetic change responsible for pandemic outbreak of influenza?
Antigenic shift
How influenza transmitted? (primarily and fomites)
- Primary: Respiratory route
- Formite: Hands & inanimate object contamination
Influenza virus retains longest on which material?
Plastic and metal (24-48 hours)
Signs and symptoms of influenza in adolescent and adults?
acute onset of fever, chills, myalgias, headache and cough
What are the general steps of influenza infection? (4)
- binding sialic acid receptors
- entering cell
- replication
- release from cell
Which treatment works for both influenza A & B?
Neuraminidase inhibitor
3 representing drugs for neuraminidase inhibitors?
- Oseltamivir
- Zanamivir
- Peramivir
2 representing drugs or matrix protein inhibitors?
- Amantadine
- Rimantadine
What strain type of influenza does matrix protein inhibitor target?
Type A strain
Review influenza steps inhibited by antiviral drugs?
Which drug H3N2 and B strains resistant to?
….
What disease H1N1 is known for to cause in human? (2)
- Flu A Associated Acute Respiratory Distress Syndrome (FLAARDS)
- multi-organ failure
Which disease associated with the picture?
FLAARDS
Which disease associated with the picture?
No disease –> normal lung
Pandemic H1N1 is an example of?
Swine Influenza
What is the similarity between Swine Influenza and Avian Influenza?
- caused by type A influenza virus
* Swine Flu: Type A H1N1
* Avian Flu: Type A H5N1
Domestic poultry with Avian Influenza can have 2 types of diseases. Which are they?
- Low Pathogenic avian influenza
- High Pathogenic avian influenza –> 100% killed
Criteria for pandemic influenza? (3)
- Emergence of a new influenza virus subtype
- Virus must infect humans and cause serious illness
- Virus must have sustained transmission and spread easily (continue without interruption) among humans
Characteristic of Inactivated influenza vaccine (IIV) (3)
- IM or IV
- Trivalent or Quadrivalent
- Killed virus
Characteristic of Live attenuated influenza vaccine (LAIV) (3)
- Intranasal
- Quadrivalent
- Live
What is the reasoning for yearly influenza vaccine?
Provide protection from high production of antibodies
What is the added benefit of the LAIV?
Cold adaptive –> protection from pulmonary infection
Where in the body does the LAIV replicate most efficiently?
Upper airway since it is cold adaptive
–> inefficiently replicate in lower airway
Compare and contrast 7 criteria of IIV and LAIV
How do we protect < 6 month age from influenza?
vaccinating pregnant women and all household members and caregivers
What is the CDC recommendation for influenza vaccine?
Include all persons aged 6 months or older who do not have a contraindication
Complication to children given aspirin when they have influenza or varicella?
Reye’s Syndrome - sever liver and brain disease
Instead of aspirin, what should be given to children with influenza or varicella?
Acetaminophen
How does antigenic shift occurs?
Gene reassortment can occur when two or more influenza viruses infect a single human or animal.
Why do we refer to pig as mixing vessels?
Pigs can be infected with virus that infect pigs, bird and human. –> allowing for reassortment of gene sequence and generate novel virus
Which influenza type is not subjected to antigenic shift?
Type B strain because it affects human only
What caused the pandemic H1N1 virus?
reassortments between swine, birds, and human virus strains
Differ the binding specificity between hemaglutinin glycoprotein and host receptors in bird and human
- Avian virus binds in an alpha-2,3 linkage
- Human virus binds in an alpha-2,6 linkage
Differ H1N1 vs. H5N1 in their tramission to human
- H1N1 result from resortment of genes between Swine influenza, Avian influenza and Human influenza
- H5N1 is due to mutation of Avian influenza Hemagglutinin such that it binds human receptor specifically
Resistance of influenza strains
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