A virus causing a worldwide lethal disease in carp and koi
fish was first reported in 1998 by Ariav et al. [1] and Bretzinger
et al. [2]. The virus was isolated by Hedrick et al. [3] and then
independently by Perelberg et al. [4]. The vast economic losses
caused by this virus led to a flurry of research activity around
the world, resulting in rapid accumulation of comprehensive
data [5–7].
The agent of the carp disease is an enveloped virus with an
icosahedral electron-dense core of 100–110 nm surrounded
by a tegument-like structure, causing it to resemble a herpes
virus [3,8]. The genome of the isolated virus comprises linear
double-stranded DNA (dsDNA) of ca 277–295 kbp [8], similar
to that of Cyprinid herpes virus-1 (CyHV-1) [9], indicating that
the genomes of this virus and CyHV-1 are larger than those of
other Herpesviridae members. The genome of this virus contains