Abstract 975 Poster Session IV, Tuesday, 5/4 (poster 152)

An outbreak of EV71 infection occurred in Taiwan in 1998. Clinical spectrum and laboratory investigation of 82 patients with virus-culture proven EV71 infections were analyzed. The age of patients ranged from 4 months to 10.5 years, wherein 88% were younger than 5 years. Hand-foot-mouth syndrome occurred in 85% of the children, herpangina in 9%, central nervous system (CNS) involvement in 26% (21/82), including seven fatal cases complicated with neurogenic shock and mortalities. Of the 21 patients with CNS involvement, 1 had aseptic meningitis, 1 meningomyelites, 12 brainstem encephalitis (7 of them complicated with neurogenic shock and pulmonary edema and died). There was no evidence of cardiogenic shock as an initial major presentation. The predominant neurological presentations were vomiting (57%), myoclonus (57%), ataxia (48%), intention tremor (29%). CNS symptoms and signs first manifested at a mean age of 3 days after occurrence of fever. Brainstem encephalitis was the cardinal feature of EV71 CNS involvement and was the main cause of death during this outbreak. Magnetic resonance image were done on 8 patients that revealed pontine enlargement and increased intensity in midbrain and pons. Brainstem encephalitis can present either with cerebellar signs initially with a mild, reversible course or with overwhelming neurogenic shock and pulmonary edema resulting in fatal outcome. Brainstem encephalitis that progressed abruptly to neurogenic shock and neurogenic pulmonary edema was considered to be indicative of poor prognosis. Early aggressive treatment and close monitoring of the neurological signs are mandatory to improve the chance of survival.