Treatment of Severe La Crosse Encephalitis With Intravenous Ribavirin Following Diagnosis by Brain Biopsy

La Crosse virus is a mosquito-borne bunyavirus that has been neglected as a cause of pediatric central nervous system (CNS) infection. The disease recurs every summer in endemic foci in the midwestern and mid-Atlantic United States in areas forested with hardwood trees, which provide breeding sites for the treehole-dwelling mosquito vector, Aedes triseriatus.¹  During hyperendemic years, the prevalence of disease in some of these areas can be remarkably high, exceeding that of bacterial meningitis.^1 2  Clinical manifestations in symptomatic cases of La Crosse encephalitis (LE) tend to cluster into a mild form or a severe form of the disease.^3-10  The usual clinical course (80% to 90%) is the mild form in which headache, fever, and vomiting frequently occur on days 1 to 3. Lethargy, behavioral changes, and/or brief seizures may occur on days 3 and 4, followed by improvement over a 7- to 8-day period. The...