A survey of Koi Herpesvirus and Carp Edema Virus in Colorcarp Cultured in Niigata Prefecture, Japan

Abstract

A survey of koi herpesvirus (KHV) and carp edema virus (CEV) was made in cultured colorcarp Cyprinus carpio. Using polymerase chain reaction (PCR), 205 fish collected from 20 culture farms located in Niigata Prefecture were examined for the presence of KHV (205 fish) and CEV (35 fish showing signs of so-called “sleeping disease”). Since the result of PCR amplification for KHV was negative in all samples, it is considered that koi herpesvirus disease does not exist in Niigata Prefecture. On the other hand, CEV genome was detected in 87.5% of “sleeping disease”-affected fish. This indicates the involvement of CEV in “sleeping disease”, though the direct cause-effect relationship has not been established.