Influenza Flashcards
Influenza, commonly known as the flu, is a highly contagious respiratory illness caused by influenza viruses. How many adults worldwide does this affect?
1 - 1.5-2%
2 - 5-10%
3 - 20-30%
4 - >50%
2 - 5-10%
Influenza, commonly known as the flu, is a highly contagious respiratory illness caused by influenza viruses. How many children worldwide does this affect?
1 - 1.5-2%
2 - 5-10%
3 - 20-30%
4 - >50%
3 - 20-30%
Influenza, commonly known as the flu, is a highly contagious respiratory illness caused by influenza viruses. In most cases the effect of the virus is self limiting, but it can also cause complications in all of the following EXCEPT which one?
1 - children
2 - elderly
3 - pregnant women
4 - chronic diseases
1 - children
Influenza, commonly known as the flu, is a highly contagious respiratory illness caused by influenza viruses. How is this typically transmitted?
1 - aerosol droplets
2 - direct contact
3 - sharing of bodily fluids
4 - sexual contact
1 - aerosol droplets
Influenza, commonly known as the flu, is a highly contagious respiratory illness caused by influenza viruses. How many people die from the influenza virus each year?
1 - 500
2 - 5000
3 - 50,000
4 - 500,000
4 - 500,000
- typically occurs due to pneumonia or respiratory failure
Once infected with influenza virus, how soon are you infective to others prior to symptoms?
1 - 1 day
2 - 3 days
3 - 7 days
4 - 2 weeks
1 - 1 day
Once infected with influenza virus, how long are you infective to others once you are symptom free?
1 - 1 day
2 - 3 days
3 - 7 days
4 - 2 weeks
3 - 7 days
Once infected with influenza, how soon is it before you typically present with symptoms?
1 - immediately
2 - 24h
3 - 48h
4 - 1-4 days
4 - 1-4 days
- symptoms typically last for 1-2 weeks
Some patients have increased risks associated with influenza. All of the following patients are at a greater risk from this virus, EXCEPT which one?
1 - adults aged >65
2 - children aged <6 months
3 - chronic comorbidities
4 - immunocompromised
2 - <6 months
Which of the following are common symptoms of the influenza virus?
1 - fever with body aches
2 - cough with sore throat
3 - runny or stuffy nose
4 - headache
5 - chills
6 - fatigue
7 - all of the above
7 - all of the above
There are a myriad of different influenza viruses, but typically how many can affect humans?
1 - >6
2 - >4
3 - 3
4 - 1
3 - 3
- influenza A, B and C
Influenza viruses A, B and C can infect humans, but which is most common?
- A
- also causes the most severe symptoms
Which 2 of the following proteins can be found on the protective envelope surface of influenza A and B?
1 - haemagluttin (H)
2 - neuraminadase (N)
3 - spike protein (S)
4 - membrane protein (M)
1 - haemagluttin (H)
2 - neuraminadase (N)
- there are lots of variations of H and N though
- H3N2 is most common to infect humans
Haemagluttin (H) and neuraminadase (N) are 2 key proteins found on the protective envelope surface of influenza A and B. There are lots of variations of H and N, but does influenza A or B have the most?
- influenza A
Which of the following proteins can be found on the protective envelope surface of influenza C?
1 - haemagluttin (H)
2 - neuraminadase (N)
3 - spike protein (S)
4 - haemagluttin esterase Fusion
4 - haemagluttin esterase Fusion
- used to enter cells
Of the 3 types of influenza, which one is most common in children?
1 - A
2 - B
3 - C
4 - all affect children equally
3 - C
causes mild illness in children
Why is influenza A able to infect people consistently?
1 - previously produced B cells die off and do not synthesis antibodies for specific H and N antigens
2 - daughter cells mutate and change H and N proteins randomly during replication
3 - strains are always different from different countries
4 - all of the above
able to evolve over time for survival
- able to do this in or outside of host cells
- called genetic drift - IMPORTANT
- called drift as its a slow process
In addition to genetic drift where influenza proteins slowly adapt for survival over time, antigenic shift can also occur in the influenza virus. What happens here?
1 - daughter cells rapidly adapt for survival
2 - influenza combined with other viruses to infect host cells
3 - 2 different cells infect the same cell and mix, causing new H and/or N proteins
4 - all of the above
3 - 2 different cells infect the same cell and mix, causing new H and/or N proteins
- linked with pandemics including the Spanish flu
- influenze virus has a segmental genome
- segmental genomes can therefore mix, similiar to miosis
- creates mixed and unique genome with new H and N proteins that are more likely to infect the host
Typically when influenza A and B enter the body, they use haemagluttin (H) to bind to what on the epithelial cells of the upper respiratory tract?
1 - CD4 receptor
2 - MHC-1 receptors
3 - sialic acid sugar
4 - any of the above
3 - sialic acid sugar
- cell then engulfs the virus in endocytosis
Once influenza virus is endocytosed by the epithelial cell it binds with what must then happen to it?
1 - negative single stranded (ss) RNA must be converted into positive ssRNA
2 - virus must enter nucleus and replace host DNA
3 - negative single stranded (ss) RNA must be chopped into small parts to be copied
4 - all of the above
1 - negative single stranded (ss) RNA must be converted into positive ssRNA
- RNA polymerase converts - into + ssRNA
- positive ssRNA is the same as mRNA which is what is needed before it can be copied by the ribosome to make proteins
One the influenza virus has copied sufficient proteins in the host cell ribosome, new viruses are made and the protein is able to leave the cell. How does this happen?
1 - binds to MHC-I molecule to leave the cell
2 - neuraminadase cleaves sialic acid sugar and buds out of the cell
3 - haemagluttin cleaves sialic acid sugar and buds out of the cell
4 - neuramindase binds MHC-II and is able to leave the cell
2 - neuraminadase cleaves sialic acid sugar and buds out of the cell
Which of the following is NOT a common complication of influenza virus?
1 - exacerbation of chronic lung disease
2 - pneumonia
3 - pneumothorax
4 - otitis media
5 - croup
6 - bronchiolitis and sinusitis
3 - pneumothorax
- croup = a common childhood infection causing a barking cough and a rasping sound when breathing. It’s usually mild but may need treatment
Children <6 months may develop which of the following as a complication of influenza?
1 - CHF
2 - encephalitis
3 - meningitis
4 - febrile seizures
2 - encephalitis
4 - febrile seizures
Reyes syndrome is a common complication that occurs in children after they have taken what?
1 - penicillin
2 - vancomycin
3 - aspirin
4 - prednisolone
3 - aspirin
- children may have this when they are infected with influenza
Reyes syndrome is a common complication that occurs in children after they have taken what aspirin to relieve symptoms caused by influenza. Which 2 the following are part of reyes syndrome?
1 - encephalopathy
2 - liver disease
3 - CHF
4 - CKD
1 - encephalopathy
2 - liver disease
- this is very dangerous
Diagnosing influenza virus is typically a clinical diagnosis. However, which 2 of the following are the most accurate methods for diagnosing a patient?
1 - viral PCR
2 - nasal or bronchial lavage
3 - blood culture
4 - viral culture of swabs from the body
1 - viral PCR
4 - viral culture of swabs from the body
if a patient presents with a suspected influenza virus, how are they treated?
1 - antibiotics
2 - oseltamivir
3 - M2 channel inhibitors
4 - supportive care (analgesia, plenty of fluids)
4 - supportive care (analgesia, plenty of fluids)
Oseltamivir can be used if patient is hospitalised and is a high risk patient
Patients with influenza are not typically treated with medications other than paracetamol as the flu is typically self limiting. However, in high risk patients, which 2 of the following may be used?
1 - neuraminidase inhibitors
2 - haemagluttin inhibitors
3 - M2 channel inhibitors
4 - spike protein inhibitors
1 - neuraminidase inhibitors
3 - M2 channel inhibitors
- used inside the host cell to help replicate
Oseltamivir and zanamivir are 2 medications that that can be given to patients who are at high risk of complications due to the influenza virus. What is the mechanism of action of this drug?
1 - neuraminidase inhibitor
2 - haemagluttin inhibitors
3 - M2 channel inhibitors
4 - spike protein inhibitors
1 - neuraminidase inhibitor
- cell cannot leave the cell and so dies
What is the most effective treatment for influenza virus?
1 - neuraminidase inhibitors
2 - haemagluttin inhibitors
3 - M2 channel inhibitors
4 - vaccinations
4 - vaccinations
- modelled on influenza proteins that are likely to dominate each season
Children <6 months are most susceptible to influenza virus. Therefore caregivers should be vaccinated to protect the child. At what age can children get the influenza vaccine?
1 - >6 months
2 - >1 year
3 - >2 years
4 - >16 years
3 - >2 years
- typically offered every autumn, but not like the typical vaccination programme
