Influenza Flashcards
influenza can cause acute ______ or viral ________
acute bronchitis
viral pneumonia
disease that has spread over multiple countries or continents
pandemic
disease that affects large amt of people within specific community, pop, or region
epidemic
disease that occurs infreq/ irregularly with no discernible temporal or spatial pattern
sporadic
a disease likely to be transmitted to people, organisms, etc (does not infer person to person (contagious))
infectious
if a disease is contagious that means
it can be passed prson to person
if a disease is infectious but not contagious that means
it can be passed to animal to animal to human, but not necessarily human to human
Influenza is an ______virus that causes respiratory infection in humans
RNA
Only influenza ___ can also infect pigs, birds (duck, geese, chickens) as well as cats, bats, and dogs among other animals
A
substypes of influenza occur due to
polymorphisms in HA and NA surface proteins
what is the vaccine target for influenza
hemagglutinin
which type of influenza virus circulates in animals as well = primes for dramatic genetic recombination and has pandemic potential
A
what type of influenza virus has the victoria and yamagata lineage
B
which influenza virus affects cattle only
D
type C influenza virus results in
possible mild illness, not threatening
nondramatic mutations of HA/NA proteins as a consequence of reduced proofreading activity of RNA polymerase
antigenic drift
antignic drift affects
1. type A
2. type B
3. both type A and B
4. neither
3
antigenic shift affects
1. type A
2. type B
3. both type A and B
4. neither
1
why is it important to get a new flu vaccine each year
1. missing it for one year will leave you susceptible to the new virus
2. we want to keep up to date on the mutants to avoid giving it to others
3. we want to build an immune library against severe illnesses in the future
4. none of the above
3
what is influenza’s route of transmission
respiratory droplet
some fomite spread
Influenza virus inhaled via respiratory droplets and binds to cells in upper airway respiratory__________ via ___________ to _________________
epithelium
haemagglutinin (HA)
sialic acid glycoprotein (SA)
T or F: sometimes influenzas will colonize the LRT
T
which of the following is true
1. influenza uses its own RNA polymerase to create mRNA
2. active viral infection is typically the culprit for mortality and morbidity
3. influenza binds via HA to SA
4. all of the above
5. 1+3
5
active viral infections leaves patients prone to
secondary infections- bacterial or fungal
patients are mostly contagious during
symptomatic phase
symptomatic period begins ___, worst at ____ into illness, then recovers over ____ period
begins day 2
worst 2-3 days into illness
recovers over 7-10 days
what is the most evident sign that it is a viral infection
sick contacts
a pt presents with sickness after a party last night. His friends are also sick. sx include SOB, nausea, vomiting, fever. This is most likely
1. viral
2. bacterial
2- simultaneously sick
what is the common clinical presentation of lower airway disease
cough- commonly nonproductive but can be productive
bloodwork in influenza sees
mild leukocytosis if any
elevated acute phase reactants
what is usually seen in diagnostic imaging for influenza
bilateral patchy opacities/ interstitial pattern
list 3 features indicative of bacterial infection
No sick contacts
Double sickening +/- Rapid acute onset (1-2 days ago)
Severe illness (relative, not a rule)
+/- purulent sputum
V high leukocytosis (>15)
Lobar infiltrate on CXR
list 3 features indicativ of viral infection
Sick contacts
Less severe or delayed onset >2-3 days
+/- clear sputum or nonproductive
Minor leukocytosis
predominant URTI sx like rhinorrhea, sneezing, congestion, sore throat is more likely
1. COVID
2. influenza
3. common cold
3
list 3 respiratory complications from influenza
ARDS
secondary bacteria pneumo
secondary fungal pneumo
CNS complications of influenza
Febrile seizures (pediatric)
Reye syndrome
RARE others (encephalitis)
GBS
cardiac complications of influenza
Exacerbation of chronic HF
Viral myocarditis/ pericarditis
pregnancy complications in influenza
↑ obstetric/ maternal complications, ↑ infant prenatal fatality, ↑ risk of prematurity, lower BW
the most common cause of death from influenza = ___ and _____
ARDS
secondary bacterial pneumo
what is the pathology of ARDS
exaggerated, dramatic, inappropriate immune response to pulmonary insult (Ex- viral infection, bacterial, trauma, foreign body aspiration, others) that leads to inability of the lung to participate in gas exchange
T or F: we must push air in to ventilate pts with ARDs
F- pushing air doesn’t work
3 attempted tx for ARDS
MV + pharmacologic lung paralysis
proning
ECMO/ECLS
what is ECMO
dialysis for the lungs
performs gas exchange, Requires major CVICU procedure + is life threatening
which of the following is false about ARDS
1. mortality rate is 80%
2. survivors commonly have CLD
3. pts of all ages can get ARDs
4. proning eventually fails
1- 50%
list 3 times to refer for influenza
suspect evolution to bacterial illness
ARDs
difficulty breathing
All pts <2yrs old with influenza
Signs of hypoxia (cyanosis, altered lvl of consciousness, difficult to rouse)
Seizure activity
Double sickening (indicative of bacterial infection)
Viral illness followed by apparent improvement, then sudden clinical worsening (double sickening)
2 ways to diagnose influenza
rapid antigen testing
molecular testing
what is the main con of RAT testing for influenza
less sensitive, if negative doesn’t rule it out
what is the major con for molecular testing for influenza
most costly + long turn around time (24-72hrs)
which 2 antivirals for influenza are marketed in canada
oseltamivir
zanamivir
oseltamivir and zanamivir are both (list 3 things)
neuraminidase inhibitors
schedule 1
BID
v well tolerated
likely safe i npregnancy
in pts requiring hospitalization
1. NAIs decreased mortality in children more than adults
2. NAIs increased the likelihood of death/ ICU if started before admission
3. NAIs decreased severe outcomes if started before admission
4. none of the above
3
in pts not requiring hospitalization, NAIs…
1. more effect is seen when given after 24hrs
2. more effect is seen when given within 12-24hrs of illnses
3. sees conflicting data on development of ARDs
4. reduces rate of ARDs
2
T or F: Oseltamivir prophylaxis, when given to high risk individuals, prevents development of symptomatic influenza (80% eff) when exposed to close contacts
T
____________ is an oral capsule med that has an indication for pts (>12yrs) at high risk of serious or complicated influenza infxns if given within 48hrs (similar to NAIs)
baloxavir marboxil
baloxavir marboxil should be given within _____
48hrs
baloxavir marboxil is ____ tolerated, ______ dose(s), and of _____ efficacy compared to oseltamivir
well tolerated
1 dose
similar eff to oseltamivir
antiviral drug resistance is
1. possible + better characterized with other viruses like HIV
2. not a clinical concern
3. may become a clinical concern in the future as the virus mutates
4. 1+3
2
what is the main issue with recognizing influenza
most pts present delayed to medical care- typically >48hrs since onset of illness
T or F: you may decide to tx with antivirals before testing results are back
T- if local outbreak and pt presents with high risk = can just start it as delayed recognition may reduce benefit
should you treat with NAI if influenza is caught <48hrs from onset, pt is immunocompetent
no
should you treat with NAI if influenza <48hrs and pt is immunocomp and has risk for severe disease
yes
should you treat with NAI if influenza caught after 48hrs and pt is hospitalized
yes
should you treat with NAI if influenza caught after 48hrs and pt has been circulating in close quarters
yes
should you treat with NAI if it’s been >48hrs of influenza and the pt is otherwise healthy, not hospitalized, and no severe illness?
no
list 3 nonpharm approaches to managing influenza
Rest and relaxation- avoid strenuous activity which could exacerbate respiratory illness if progressive pneumonia
Cold compresses on forehead for fever
Maintenance of fluid and food intake (esp elderly, reduced PO intake = develop AKI or electrolyte disturbances which would require admission)
list 2 pharm measures for comfort in influenza
APAP/ ibuprofen reasonable for fever and muscle aches
OTC antinauseants for N/V
