Report on the first two confirmed autochthonous cases of West Nile virus encephalitis in Catalonia, Spain

BackgroundWest Nile virus (WNV) is a mosquito-borne flavivirus that can cause Central Nervous System infection in humans. Previous autochthonous cases of WNV encephalitis have been described in Spain, but none in Catalonia.Materials and methodsWe report on the first two autochthonous cases of encephalitis in humans caused by the West Nile virus (WNV) diagnosed in Catalonia (northeastern region of Spain).ResultsAn old married couple presented with clinical and biological signs compatible with viral encephalitis. Acute and convalescent serum samples showed IgM and IgG positivity for WNV. In addition, IgM was also detected in cerebrospinal fluid in the male patient. The serological results were later confirmed by microneutralization assays.ConclusionsWNV infection must be considered in patients presenting with meningoencephalitis with viral CSF characteristics when common pathogens are excluded.