Background: West 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 methods: We 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).
Results: An 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.
Conclusions: WNV infection must be considered in patients presenting with meningoencephalitis with viral CSF characteristics when common pathogens are excluded.
Keywords: West Nile virus; arboviruses; encephalitis; viruses.