[P2-18] Accumulation of three pediatric cases of acute flaccid myelitis in autumn 2015 in Nagasaki, Japan
【Introduction】During the outbreak of enterovirus D68 (EV-D68)-associated respiratory diseases in North America in autumn 2014, a number of cases of acute flaccid paralysis (AFP) were reported. Similarly, accumulation of AFP cases was observed in Japan during the outbreak of EV-D68 in autumn 2015. During the season, we accumulatively experienced three AFP cases in Nagasaki. 【Case presentations】 Patients were a 12-year-old girl, a 4-year-old boy and a 2-year-old girl. They all developed AFP 5-9 days after respiratory symptoms. T2-weighted images of the spinal MRI showed high intensity lesions, particularly affecting the anterior horns in all three cases. The CSF studies indicated pleocytosis and increased protein levels in 2 of them. The peripheral nerve conduction studies showed reduction of F wave incidence in all of them. They were treated with intravenous immunoglobulin, methylprednisolone pulse therapy, and plasma exchange, none of which appeared effective. They all had severe to mild sequelae. EV-D68 was not detected in nasopharyngeal specimens from all three cases.【Discussion】Results from the CSF, MRI and peripheral nerve conduction studies were compatible to myelitis with the involvement of the anterior horns in all three cases. Although etiological roles of EV-D68 in AFP were strongly suspected, we could not identify EV-D68 from any of our patients. Since EV-D68 can be detected only in the early stage of the infection, sample collection from our cases might be too late. Further studies are needed to demonstrate the roles of EV-D68 in the pathogenesis of AFP.