Influenza - Block 3 Flashcards
What is the difference between influenza A and B?
A: Regular, seasonal epidemics of the flu
B: sporadic outbreaks in long term care facilities
What are the characterisitcs of influenza C?
Not responsible for seasonal flu, but causes sporadic URT illness
* No vaccine coverage
What is hemagglutinin? How many subtypes are there?
Allows the influenza virus to enter host cells
16 subtypes
What is the neuraminidase? How many subtypes?
Allows the release of new viral particles from host cells
9 subtypes
What are the primary subtypes of influenza A?
H3N2
H1N1
What is the difference between antigenic drift and shift?
Drift: point mutations which is a reason for changing flu vaccines
Shift: Genetic reassortment -> new subtype
Transmission
Inhalation and virus shed from RT
Incubation time of flu?
1-7 days
Respiratory droplet precautions?
- Wash or gel hands
- Wear mask
- Wear eye protection
RF of flu?
- Adults ≥65 YO
- Children ≤4 YO
- Persons with underlying medical conditions
- Predisposing facotrs (pregnancy, immunosuppred, obesity, nursing home)
Classical sx of flu?
- Rapid onset of fever
- Myalgia
- HA
- Malaise
- Nonproductive cough
- Sore throat
- Rhinits
How long does it take for flu sx to resolve?
3-7 days
Presentation primary viral pneumonia?
- Bilateral findings of respiratory distress syndrome on chest X ray
- Cyanosis
- Dyspnea
- Hypoxia on blood gas
Presention of secondary bacterial pneumonia?
- Cough
- Sputum production
- Consolidation on chest X ray
Lab tests associated with flu?
- Nasopharyngeal swab or aspirate is more sensitive
* Disease course: Increased viral shedding and detection early in disease improves sensitivity
* Younger pateint shed more - Rapid antigen detection (RAD): least sensitive
- Rapid molecular assay (RAM): gold standard (RT-PCR)
Nonpharm for flu tx?
- Get adequate sleep and maintain a low level of activty
- Appropriate fluid intake
- Throat lozenge, warm tea, soup
Non pharm for prevention?
- Hand hygiene
- Basic respiratory etiquette
- Contact avoidance
- Vaccination
Who and when should someone get vaxed?
Who: 6 months and older
When: October or Novemeber
Decribe activity of inacitivated and live?
In: produces high serum IgG antibody response (tri and quadrivalent)
Live: produces lower IgG response and high serum IgA mucosal response (quadrivalent)
Inactiated influenza vaccine (IIV) types?
Afluria, Fluarix, FluLaval, Fluzone
High dose: Fluad, FLuzone HD
Live attenuated flu vaccine (LAIV)?
Flumist
Non egg based flu vaccine types?
Flublok
Flucelvax
Who should recieve 2 doses of flu vax?
f no previous vaccination, children 6 months to < 9 y/o should receive two doses of IIV at least 4 weeks apart (i.e. a booster dose)