Eastern equine encephalitis: a classical case.

Abstract

We present the case of a 40-year-old man with rapidly deteriorating acute meningoencephalitis, finally diagnosed as eastern equine encephalitis (EEE). The course and timing in this patient are quite characteristic. EEE is an arthropod borneviral illness in which the mosquito serves as the vector. It is amongst the most severe of the arbovirus encephalitides and has a high mortality and morbidity. In nonfatal cases, residual neurological deficits are often severe and permanent. North American lineage of EEE is mainly found in the northeast especially along the coastal areas. EEE is primarily found in horses and other domestic mammals that remain outdoors nocturnally. In humans, symptoms range from nonspecific constitutional features to catastrophic neurological sequelae including death. Hyponatremia and increased cerebrospinal fluid (CSF) white blood cell count are independent predictors of poor outcomes. Diagnosis is suggestive by demonstrating IgM antibody in blood or CSF samples and can be confirmed by other serologic assay including immunohistochemistry and polymerase chain reaction (PCR). Measures recommended by the Center for Disease Control (CDC) for prevention include using repellents, protective clothing, screens, and eradication of mosquito breeding areas. EEE remains without cure and prevention is the best medicine.