What is the typical approach to diagnosing influenza?

What is the typical approach to diagnosing influenza?

• A. Usually clinical; rapid influenza test or viral culture
• B. CT scan is diagnostic
• C. Blood culture is standard
• D. Sputum Gram stain

Answer: (A)

Influenza is usually diagnosed from the clinical picture—sudden onset of fever, cough, myalgias, and malaise during flu season—so most cases don’t require lab confirmation to manage symptoms and start antivirals if indicated. Testing is used selectively to confirm infection or guide infection control and therapy: a rapid influenza diagnostic test provides quick results to help decide on antiviral use and isolation, while viral culture is more sensitive and useful for confirmation or surveillance but takes longer to yield results. Other tests aren’t used to diagnose influenza: CT scans aren’t diagnostic and are reserved for evaluating complications, blood cultures look for bacteremia, and sputum Gram stain detects bacteria, not the influenza virus.

Influenza is usually diagnosed from the clinical picture—sudden onset of fever, cough, myalgias, and malaise during flu season—so most cases don’t require lab confirmation to manage symptoms and start antivirals if indicated. Testing is used selectively to confirm infection or guide infection control and therapy: a rapid influenza diagnostic test provides quick results to help decide on antiviral use and isolation, while viral culture is more sensitive and useful for confirmation or surveillance but takes longer to yield results. Other tests aren’t used to diagnose influenza: CT scans aren’t diagnostic and are reserved for evaluating complications, blood cultures look for bacteremia, and sputum Gram stain detects bacteria, not the influenza virus.