Does the Japanese encephalitis virus (JEV) represent a threat for human health in Europe? Detection of JEV RNA sequences in birds collected in Italy.

Autochthonous cases of Japanese encephalitis (JE) have never been reported in Europe, where there is virtually no circulation of the virus [1]. However, in the issue of Eurosurveillance published on 12 July 2012, Ravanini et al. [2] reported the detection of an RNA sequence of the Japanese encephalitis virus (JEV) NS5 gene in one pool of Culex pipiens mosquitoes collected in north-eastern Italy during the summer of 2010. Unfortunately, the sequence was relatively short (167 bp), and attempts to amplify longer sequences using primers targeted to E, NS5 and NS3 genes and to isolate the virus on cell cultures failed. To support their findings, the authors cited a previous study reporting the identification of JEV RNA in bird samples collected in Tuscany, a neighbouring Italian region, a decade before [3], and noted the lack of information on viral sequences in that study. Here we provide the results of molecular testing on bird tissue samples, which appear to confirm recent findings on JEV presence in Italy.