Snapshot A 26-year-old man presents to the emergency department with worsening muscle weakness over the course of 3 days. Prior to developing muscle weakness, he reports acquiring flu-like symptoms, such as a sore throat, myalgias, and headache. Social history is significant for recently emigrating from Pakistan. He does not believe to ever being vaccinated. On physical examination, there is asymmetric proximal muscle weakness of the lower extremities. After extensive workup, his PCR was positive for poliovirus. Introduction Clinical definition flaccid paralysis secondary to poliovirus infection Epidemiology incidence due to mass vaccination, the virus has been eradicated in most of the world risk factors lack of vaccination Pathogenesis this (+) ssRNA virus is spread via the fecal-oral route and replicates and disseminates throughout the body which may involve the motor neurons (e.g., anterior horn cells) Prognosis 2-10% mortality rate in paralytic poliomyelitis Presentation Symptoms asymptomatic (~70% of cases) flu-like syndrome such as myalgias sore throat headache asymmetric weakness fasciculations Physical exam decreased muscle tone decreased or absent reflexes proximal > distal and legs > arm weakness normal sensory exam Studies Labs polymerase chain reaction (PCR) of poliovirus RNA this is the gold standard Differential Other enteroviruses such as coxsackievirus Guillain-Barre syndrome Acute intermittent porphyria Treatment Conservative supportive treatment indication there is no specific treatment available and thus management is aimed at improving symptoms, such as pain and fever control and physical therapy mechanical ventilation may be needed in cases of respiratory failure therefore, it is best to prevent development of poliomyelitis via vaccination Complications Postpolio syndrome occurs years after recovery from poliomyelitis patients present with fatigue, weakness, myalgias, arthralgias, and decreasing functional status