Polio clinical spectrum includes:

• A. Mild flu-like symptoms
• B. Severe respiratory paralysis only
• C. Severe limb paralysis only
• D. Mild flu-like symptoms that can progress to severe respiratory or limb paralysis, or death

Answer: (D)

Polio presents along a spectrum from mild illness to life-threatening paralysis. Many infections cause only mild, flu-like symptoms or are asymptomatic. In some people, the virus can invade motor neurons and cause paralytic poliomyelitis, which may affect the limbs, the muscles involved in breathing, or both, and can lead to ventilatory failure and death. The choice that describes starting with mild flu-like symptoms and potentially progressing to severe respiratory or limb paralysis, or death, best captures this range. The other options describe only a single end of the spectrum or restrict the clinical picture, which doesn’t reflect the variability seen with polio.