- Ilaria Mussetto1,* , Andrea Bongiovanni1,* , Francesca Colavita1 , Cristina Giambi2 , Marcello Giovanni Sala3 , Cosmo Del Borgo4 , Fabrizio Carletti1 , Maria Teresa Scicluna3 , Alessandro Zerbetto2 , Angela Corpolongo1 , Federico Romiti3 , Maria Beatrice Valli1 , Stefania Vaglio5 , Roberto Giammattei6 , Paola Scognamiglio1,7 , Gabriella De Carli1 , Alessandro Agresta1 , Claudio De Liberato3 , Giuseppe Di Luzio8 , Florindo Micarelli2 , Emanuele Nicastri1 , Andrea Siddu7 , Valeria Ficarelli7 , Enrico Girardi1 , Fabrizio Maggi1 , Francesco Vairo1 , the Lazio WNV Outbreak Group9
In July–18 August 2025, 171 autochthonous cases with West Nile virus (WNV) infection were confirmed in Lazio, Italy: four asymptomatic blood donors, 110 with WNV fever, 57 with neuroinvasive syndrome and nine deaths. WNV lineage 2 was detected in two neuroinvasive cases. Infection with WNV was confirmed in 28 horses, five crows and a Culex pipiens pool. We present the preliminary epidemiological and phylogenetic analysis of the outbreak and the public health measures taken within a One Health approach.