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)
Who should recieve high dose?
≥65YO (lacks a strong antibody response)
ADR of flu vac?
- SOreness at inj site
- Fever
- Malaise
Relationship between GBS and flu vac?
Should be avoided in persons who are not at high risk for influenza complications and who have experienced GBS within 6 week
Relationship between autism and flu vac?
The multidose vials of intramuscular IIV contain trace to small amounts of a preservative, thimerosal -> but untrue
Route of Live vac? Indication? CI?
Route: Intranasal
Indication: 2-49 YO
CI: PRegnancy or immunocompromised
Pros and cons of live vac?
Pro: acts on site of viral entry
Limitations: expensive
* Should not be administered until 48 hrs after flu antiviral therapy
* Influenza antiviral drugs should not be administered for 2 weeks after the administration of vaccine
Vaccinations for special populations?
Annual IIV vaccinations for pregnant, IC
Who should be treated with antivirals?
- Person of any age who are hospitalized with flu
- Outpatients severe or progressive illness
- Outpatients at high risk of complications from flu with chronic med conditions
- ≤2 or ≥65 YO
- Pregnant or 2 weeks postpartum
OTC for flu?
- APAP
- NSAIDs
- Cold/flu products for sx
Benefits of using antiviral drugs?
- Most effective within 48Hrs of the onset of tillness
- Shorten the duration of illness and provide sx control
NA inhibitors examples?
Oseltamivir (Tamiflu)
Zanamivir (Relenza)
Peramivir (Rabpivab) - IV
Cap-dependent endonuclease inhibitor types?
Baloxavir (Xofluza)
Benefits of NA inhibitors?
Shortened symptom duration in adults by 0.5 to 1 day
* Benefits of using it within 12 hrs of illness onset up to 48 hrs after onset of illness
Caution of NA inhibitors?
Neuropsychiatric events
OSeltamivir
Indication, Tx duration, Form, ADR
Indication: 14 days and older
Duration: 5 days
Form: PO
ADR: GI upset, HA
Zanamivir
Indication, Tx duration, Form, ADR
Indication: ≥7 YO
Duration: 5 days
Form: DPI
ADR: bronchospasm, sinusitis, DZ
Counseling point for Relenza?
- Should not be manipulated
- Bronchodilator prior to zanamivir
- Same time each day
Caution with Relenza?
Bronchospasm
Decreased lung function
Peramivir
Indication, Tx duration, Form, ADR
Indication: 2YO+
Duration: 1 days
Form: IV
ADR: diarrhea
Indications for using peramivir?
Patients unable to tolerate or absorb PO or enterically administer oseltamivir due to gastric stasis, malabsoprtion, or GI bleeding
Adult dosing for NA inhibitors?
Oseltamivir/Zanamivir: 5 days
Peramivir: 1 days
MOA of Baloxavir marboxil (Xofluza)? Indication? Counseling?
MOA: interferes with viral RNA transcription and blocks virus replication
Indication:
* 48 hrs of illness onset
* 5YO and older
* Uncomplicated flu who are at high risk
Counseling: Dairy products, Calcium-fortified bevarages, cation-containing laxatives or antacids
Benefits of using Baloxavir marboxil? Caution?
Benefits, Caution, Dosing
Benefits: Decreased duration of illness by 2.5 days
Caution: resistance on therapy developed in clinical trials
Dosing: ≥5YO
Antiviral indicated for pregnancy?
Oseltamivir
* Zanamivir: respiratory complications
* Baloxavir: not recommended for pregnancy
Evaluation for antiviral tx?
- Monitor daily for s/s
- s/s resolution in 1 week
How should consider postexposure prophylaxis?
- Not to replace vaccination
- Given 48 hrs after exposure
- 2 week bridge in high-risk individuals after vaccination
- Those unable to recieve a vaccination
- May not respond immunologically to vaccine adminstration
Medications used for postexposure prophylaxis?
NAI: oseltamivir, zanamivir
Cap dependent endonuclease inhibitor: baloxavir
Duration of postexposure prophylaxis?
Tamiflu/Zanamivir: 10 days
Baloxavir: 1 days
Lower respiratory tract sx of RSV?
Bronchiolitits and pneumonia
Supportive care for RSV?
- Supplemental O2
- Hydration
- Mechanical ventilation
RSV RF?
- Premature birth
- Chronic lung dx
- Congenital heart disease
- Immunodeficiency
- Airway abnormalities
Pharm tx for RSV?
- Inhaled ribavirin: only for severely IC or high risk patients
- Inhaled beta-2 agonists/racemic epi
- Corticosteroids
- Inhaled hypertonic saline
- Antibiotics
RSV prophylaxis non pharm?
- Avoid crowds during RSV season
- Good hand hygiene
Use of palivizumab for RSV prophylaxis?
Cost-effective only for infants at high risk for hospitalization:
1. Born at<29 weeks gestation and are<1 year old at the start of RSV season
2. <1 year old w/ chronic lung disease of prematurity
3. <1 year old with hemodynamically significant congenital heart disease
4. Chronic lung disease of prematurity in the second year of life and have received treatment with chronic corticosteroids or diuretics or have had a continued need for oxygen therapy within 6 months of RSV season
How many Palivizumab dose are in RSV prophylaxis?
5 doses
Use of Nirsevimab (Beyfortus) for RSV prophylaxis? Caution?
Long acting monoclonal antibody for use in the following infants and young children:
* All infants<8 months of age who are either born during or entering their first RSV season
* 8 months through 19 months who are at increased risk of severe RSV disease and who are entering their second RSV season
Caution: Children who receivenirsevimabshouldNOTreceivepalivizumabin the same RSV season.
Vaccination indications for RSV?
Arexvy: >60 YO
Abrysvo: >60YO, pregant patients 32-36 weeks gestation
