Vaccine-associated paralytic poliomyelitis caused by contact infection

We encountered an adult patient with acute anterior poliomyelitis (AAP), whose monoparesis developed 28 days after his son's immunization with oral poliovirus vaccine (OPV). Neurological and electrophysiological examinations suggested that his muscular wasting of the left lower limb was due to a lower motor neuron disorder, and magnetic resonance imaging revealed the responsible lesion in the left anterior horn at the thoracolumbar junction. His stool was found to include poliovirus type 3, mainly originating from Sabin 3 by neutrization antibody and PCR-restriction fragment length polymorphism method. This indicated that the AAP resulted from contact with his son. This patient raises the question about OPV in polio-free countries.