Nowotny et al.
Neurotropic tick-borne flavivirus in alpine chamois (Rupicapra rupicapra rupicapra), Austria, 2017, Italy, 2023. Viruses. 2025;17(1):122. doi:10.3390/v17010122
Until recently, the European subtype of the tick-borne encephalitis (TBE) virus was the only encephalitis-associated flavivirus known to be present in Central Europe. However, a newly identified flavivirus, closely related to the TBE virus, has been detected in the Alps and has been provisionally named alpine chamois encephalitis virus (ACEV).
Postmortem and pathological investigations of three alpine chamois—one from near Salzburg, Austria, and two from the Piedmont and Lombardy regions of Italy—revealed TBE-like neuropathological features. Nucleotide sequences detected in ticks collected from these animals, as well as from other ticks in the region, formed a single monophyletic group with sequence similarity ranging from 94.75% to 97.31%. This group also included the Spanish goat encephalitis virus (SGEV) and shared a common ancestor with Louping ill virus (LIV) but clustered separately from SGEV, Greek goat encephalitis virus (GGEV), and Turkish sheep encephalitis virus (TSEV).
Genetic analysis showed that ACEV shares 94.77% to 97.32% similarity with SGEV, 90.31% to 90.62% with LIV, and 86.73% to 86.97% with the European subtype of the TBE virus. However, its zoonotic potential remains unclear. Experimental studies indicate that ACEV is lethal to intracranially inoculated suckling mice and subcutaneously inoculated 23-day-old mice. Moreover, serological tests designed for TBE virus cross-react with ACEV, suggesting antigenic similarities between the viruses.
To facilitate further research, a cell-culture isolate of ACEV has been deposited in the European Virus Archive platform.