First occurrence of ranavirus in the Scandinavian peninsula

Emerging infectious diseases (EIDs) pose a major threat to global amphibian populations, contributing to widespread mortality and species extinctions. Among EIDs, those caused by the fungal pathogens Batrachochytrium dendrobatidis ( B d ) and B. salamandrivorans ( Bsa l ), and viruses in the genus Ranavirus (Rv), represent the most significant threats to amphibian biodiversity. Here, we tested for occurrence of Rv in 3 different locations in southeastern Sweden. Using a quantitative PCR assay, complemented by a secondary PCR-based validation method targeting the viral major capsid protein gene and additional 5 partial sequences, we detected Rv in 2 of 3 locations and in 5 out of 43 individuals tested. This is the first record of Rv occurrence reported at such high latitudes in northern Europe and the first from the Scandinavian peninsula, contributing important insights into infection prevalence in northern amphibian populations. These findings establish a basis for the conservation of vulnerable populations.