Carp oedema virus disease outbreaks in Czech and Slovak aquaculture

This work describes the first confirmed cases of carp oedema virus disease (CEVD) in Slovakia and the Czech Republic and the phylogenetic analysis of Czech and Slovak carp oedema virus (CEV) isolates. Four cases of disease outbreak in the Czech Republic are described, the oldest dating from mid-May 2013 and one case from Slovakia dating from May 2019. In all cases, virus presence was confirmed using nested PCR. PCR products were sequenced and compared with 357-bp nucleotide sequences encoding the CEV P4a protein in GenBank. In four cases of disease outbreak (three common carp breeding facilities and one koi garden pond), CEV detected belonged to genogroup I. In one case (koi garden pond), fish were confirmed as infected with CEV from genogroup II. This work complements data on CEV occurrence in European countries and contributes to a better understanding of the pathways leading to transmission of the virus throughout Europe.