Q: Which of the following best describes the genome of the influenza virus?

Eight segments of single-stranded negative-sense RNA ($$8 \times ssRNA)$$

Question 1

Which of the following best explains why a new influenza vaccine is required each year?

Accepted Answer

The influenza virus undergoes frequent antigenic drift, resulting in new strains with mutations in hemagglutinin (HA) and neuraminidase (NA) proteins.

Question 2

Which statement correctly describes the difference between positive-sense and negative-sense single-stranded RNA viruses?

Accepted Answer

Positive-sense RNA can be directly translated by host ribosomes, while negative-sense RNA must first be transcribed into mRNA.

Question 3

A patient develops severe respiratory distress 10 days after initial symptoms of SARS-CoV-2 infection. Which complication is most likely responsible, and what is the recommended treatment?

Accepted Answer

Acute Respiratory Distress Syndrome (ARDS); treat with dexamethasone to reduce inflammation.

Question 4

Which of the following best describes antigenic shift in influenza viruses?

Accepted Answer

Recombination of genetic material from different influenza viruses co-infecting the same host, resulting in a novel virus strain.

Question 5

Which laboratory method is commonly used to distinguish between influenza virus strains during an outbreak?

Accepted Answer

PCR-based molecular testing to detect specific viral RNA sequences.

Question 6

What is the role of neuraminidase (NA) in the influenza virus life cycle?

Accepted Answer

Facilitates the release of newly formed virions from the host cell by cleaving sialic acid residues.

Question 7

A new strain of influenza emerges after pigs are co-infected with human and avian influenza viruses. Which process is responsible for this event?

Accepted Answer

Antigenic shift

Question 8

Which of the following is a key difference in the pathogenic mechanisms of influenza virus and SARS-CoV-2?

Accepted Answer

SARS-CoV-2 uses the ACE2 receptor for cell entry, while influenza uses hemagglutinin (HA) to bind to sialic acid receptors.

Question 9

Which of the following treatments is recommended for hospitalized patients with severe COVID-19?

Accepted Answer

Dexamethasone, anticoagulant therapy, and antiviral drugs such as Paxlovid or Remdesivir.

Question 10

Which statement about the epidemiology of SARS-CoV-2 is supported by recent studies?

Accepted Answer

Booster vaccine efficacy against Omicron infection drops to 30% after 9 months, but protection against severe disease lasts much longer.

Question 11

Which of the following best describes the genome of the influenza virus?

Accepted Answer

Eight segments of single-stranded negative-sense RNA ($$8 	imes ssRNA)$$

Question 12

Which step in the influenza virus life cycle is directly inhibited by oseltamivir?

Accepted Answer

Release of virions from the host cell membrane

Question 13

A patient with COVID-19 develops confusion and tiredness months after recovery. Which term best describes these symptoms?

Accepted Answer

Long-term effects (Long COVID)

Question 14

Which of the following is a reason why patients with influenza are more susceptible to secondary bacterial infections?

Accepted Answer

Death of infected epithelial cells eliminates the lungs’ epithelial lining, reducing barrier protection.

Question 15

Which of the following statements about hybrid immunity to SARS-CoV-2 is correct?

Accepted Answer

Hybrid immunity (infection plus vaccination) provides greater and longer-lasting protection than either alone.

Question 16

Which of the following is a common symptom during the prodromal phase of both influenza and SARS-CoV-2 infection?

Accepted Answer

Fever and malaise

Question 17

Which of the following best explains why negative-sense RNA viruses require an additional step before protein synthesis?

Accepted Answer

Negative-sense RNA must be transcribed into positive-sense mRNA by viral RNA-dependent RNA polymerase before translation.

Question 18

Which of the following is a plausible reason for the increased risk of stroke in some COVID-19 patients?

Accepted Answer

Diffuse clotting and vascular damage associated with severe SARS-CoV-2 infection.

Question 19

Which of the following best describes the mechanism of action of baricitinib in the treatment of severe COVID-19?

Accepted Answer

Baricitinib blocks the JAK pathway, reducing inflammation and modulating the immune response.

RNA Viruses: Influenza and SARS-CoV-2 – Structure, Pathogenesis, Epidemiology, and Prevention

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