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Questions and Answers
What is the primary cause of a runny nose during the phase of infection?
What is the primary cause of a runny nose during the phase of infection?
What complication can arise from the spread of the virus to the lower respiratory tract?
What complication can arise from the spread of the virus to the lower respiratory tract?
Which symptom is NOT typically associated with the abrupt onset of influenza?
Which symptom is NOT typically associated with the abrupt onset of influenza?
Which of the following tests can help diagnose influenza?
Which of the following tests can help diagnose influenza?
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When are antiviral medications most effective for influenza treatment?
When are antiviral medications most effective for influenza treatment?
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What is the action of oseltamivir (Tamiflu) in treating influenza?
What is the action of oseltamivir (Tamiflu) in treating influenza?
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What is a common side effect of antiviral medications for influenza?
What is a common side effect of antiviral medications for influenza?
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Which of the following is a supportive care measure for managing influenza symptoms?
Which of the following is a supportive care measure for managing influenza symptoms?
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Which types of influenza viruses are known to cause significant illness in humans?
Which types of influenza viruses are known to cause significant illness in humans?
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How are influenza A viruses categorized?
How are influenza A viruses categorized?
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What is the primary cause of influenza transmission?
What is the primary cause of influenza transmission?
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What typically characterizes an epidemic of influenza?
What typically characterizes an epidemic of influenza?
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Which influenza type is known to cause milder illness and is not associated with pandemics?
Which influenza type is known to cause milder illness and is not associated with pandemics?
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What happens when a new strain of influenza A virus reaches humans?
What happens when a new strain of influenza A virus reaches humans?
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How long is the typical incubation period for the influenza virus?
How long is the typical incubation period for the influenza virus?
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Which cells does the influenza virus primarily target in the respiratory tract?
Which cells does the influenza virus primarily target in the respiratory tract?
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Study Notes
Influenza Overview
- Influenza (Flu) is a leading cause of upper respiratory tract infections in humans.
- More contagious than bacterial respiratory infections.
Classification of Influenza Viruses
- Four serotypes: A, B, C, and D.
- Only types A and B cause significant illness in humans.
Influenza A
- Subtyped based on two surface proteins: hemagglutinin (H) and neuraminidase (N).
- Naming convention includes both H and N types (e.g., H3N2).
- Most common and virulent flu virus, infects multiple animal species.
- New mutations can lead to pandemics as humans have no immunity.
- H1N1 (swine flu) emerged in 2009, resulting in a global pandemic.
- Epidemics are localized outbreaks caused by variants of circulating strains.
Influenza B, C, D
- Influenza B and C only infect humans and are not divided into subtypes.
- B is associated with regional epidemics, less severe than A.
- C causes mild illness, does not lead to epidemics or pandemics.
- Influenza D affects only animals.
Incubation and Transmission
- Incubation period lasts from 1 to 5 days.
- Infectious starting one day before symptoms appear and for about 5-7 days after onset.
- Transmission occurs through inhalation or ingestion of viral particles from droplets.
Pathophysiology
- Virus attaches to and enters respiratory epithelial cells, replicating within.
- This triggers inflammatory and immune responses.
- Damage to mucous-secreting and ciliated cells leads to symptoms like a “runny nose.”
- If the virus spreads to the lower respiratory tract, it can compromise natural defenses and lead to complications, such as bacterial pneumonia.
Clinical Manifestations
- Abrupt onset of symptoms, including chills, fever, malaise, headache, cough, sore throat, and fatigue.
Diagnostic Studies
- Diagnosis based on health history, physical assessment, and community outbreak awareness.
- Viral culture from respiratory samples helps identify virus type and strain.
Antiviral Medications
- Effective within 48 hours of symptom onset, they can shorten illness duration, reduce symptom severity, and prevent complications.
- Common antivirals:
- Oseltamivir (Tamiflu): Oral; inhibits neuraminidase enzyme.
- Zanamivir (Relenza): Inhaled; similar action to oseltamivir.
- Peramivir (Rapivab): Intravenous option for severe cases.
- Baloxavir marboxil (Xofluza): Targets different stages of viral replication.
- Potential side effects include gastrointestinal symptoms and neurological issues (rare).
Supportive Care
- Hydration: Maintain fluid intake to prevent dehydration.
- Rest: Encourages recovery and supports immune response.
- Fever Management: Use of antipyretics (e.g., acetaminophen, ibuprofen).
Symptomatic Relief
- Decongestants: Alleviate nasal congestion.
- Cough suppressants and other supportive medications for symptom management.
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Description
This quiz covers the essential aspects of influenza, including its classification, serotypes, and the significance of Influenza A, B, C, and D. Understand the modes of transmission, illness severity, and the impact of mutations on public health. Test your knowledge on this critical respiratory infection.
