Review Question - QID 214478

A 5-year-old boy is brought to the physician by his parents with weakness in both of his legs. The parents note that the child began complaining of numbness and altered sensation in his legs 2 days ago, but it has gotten progressively worse in the past 48 hours. They also mention that the boy had a fever and 1 episode of diarrhea prior to the onset of leg weakness. His temperature is 101.2°F (38.4°C). Physical examination reveals motor weakness, poor muscle tone, and diminished reflexes in both lower limbs. The child is up to date on all of his scheduled vaccinations and has previously been vaccinated against poliovirus. A pathogen from which of the following viral families is the most likely cause of this patient’s symptoms?