Western equine encephalitis: a pediatric case report.

Western equine encephalitis (WEE) is a zoonotic disease caused by an RNA virus of the genus Alphavirus, and humans are accidental hosts. Although most patients do not develop symptoms upon infection, children are at higher risk for neurological involvement. Here we describe the case of a previously healthy 13-year-old male patient who lived in an urban area in the province of Buenos Aires, Argentina, who was hospitalized and diagnosed with meningoencephalitis. Due to the torpid course of his condition and because none of the most frequent microorganisms were isolated, a test for IgG antibodies for WEE virus in blood and cerebrospinal fluid was requested; both samples were positive. WEE virus is often an underdiagnosed cause of encephalitis and should be taken into consideration in both rural and urban areas.