Shamonda virus EU1 in Northern Italy, August 2026.

Abstract

Background Following the emergence of a novel Shamonda-like virus (SHAV) in Europe, suspected clinical cases in dairy cattle were reported in Northeastern Italy. Investigation was required in dairy cattle in Northeastern Italy. Methods Samples were collected from 28 farms displaying fever and reduced milk yield and were screened using molecular methods (PanSimbu real-time RT-PCR followed by Sanger sequencing and differential PCRs for SBV/BTV). Positive samples were subsequently confirmed by Sanger sequencing and selected samples underwent whole-genome sequencing using a metagenomic approach. Results Twenty-four among sera and blood samples from 12 farms tested positive for SHAV. WGS confirmed that Italian strains share maximum identity with the European SHAV-EU1 clade. Limitations This study concerns the results of clinical investigations on suspected cases in the two autonomous provinces of Trento and Bolzano. At present, it is not possible to infer on the circulation of the virus in other Italian provinces. Conclusions This study documents the first detection and genetic characterization of SHAV-EU1 in Italian cattle, indicating active circulation of this virus across Europe. Its identification in two north-eastern Italian provinces does not rule out wider, undetected circulation. In this regard, assessing its geographical extent requires careful evaluation, just as much remains to be discovered about its host range and the severity of symptoms.