Dear colleagues, With reference to the recent report of Circulation of Cetacean Morbillivirus in Striped Dolphins in the Western Mediterranean Coast (Catalonia) (Domingo, Sept. 21th 2016) the Italian Stranding Network underline the increase in the mortality rate among cetaceans in the Italian seas, which has been noted since July-August 2016, mainly in southern Italy, along the Ionian coastline. We would like to bring to your attention the results of diagnostic investigations for Dolphin Morbillivirus performed on stranded animals at national level. Considering the post mortem investigations performed by Istituti Zooprofilattici Sperimentali (IIZZSS), coordinated by the Italian reference center for diagnostic investigations on stranded marine mammals (C.Re.Di.Ma.) from the beginning of the year, a CeMV disease was diagnosed in 25 animals. Although part of the analysis is still ongoing, Dolphin Morbillivirus was detected by biomolecular assay in several tissues from all animals. Seven of these were also positive by IHC investigations. In some of them we observed histopathological lesions suggestive of morbillivirus infection, as we haven’t seen for many years. CeMV was reported several times during the last 9 years affecting several species (i.e. fin, sperm and beaked whales) (Mazzariol et al., 2016, Mazzariol et al., 2017; Centelleghe et al., in press) being constantly found in striped and bottlenose dolphins after the last mortality outbreak in 2013 in the Italian waters. The viral genome sequencing suggested the circulation of the same virus since the 2006-07 epidemic within the Mediterranean waters with very mild changes (Beffagna et al., in press). Despite these observations, our preliminary data in this very recent unusual mortality event support the hypothesis of a new circulation of CeMV causing death in the Ionian striped dolphin population. The phylogenetic analysis performed on the first two strains sequenced could support the presence of a branch clustered with the Portuguese and Galician strains (Bento al. 2016) and separated from the Mediterranean ones. We are grateful if other Mediterranean nations could share with us similar information, in order to get a punctual and more complete photography on what is going on. Cristina Casalone DMV Centro di Referenza Nazionale per le indagini diagnostiche sui Mammiferi Marini spiaggiati- C.Re.Di.Ma.- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta Via Bologna 148, 10154 TORINO - ITALIA Tel. +(39) 011 2686296 e-mail: credima@izsto.it<mailto:credima@izsto.it> cristina.casalone@izsto.it<mailto:cristina.casalone@izsto.it> www.izsto.it<http://www.izsto.it/>