Is There Any Species Specificity in Infections with Aquatic Animal Herpesviruses?-The Koi Herpesvirus (KHV): An Alloherpesvirus Model

Most diseases induced by herpesviruses are host-specific; however, exceptions exist within the family Alloherpesviridae. Most members of the Alloherpesviridae are detected in at least two different species, with and without clinical signs of a disease. In the current study the Koi herpesvirus (KHV) was used as a model member of the Alloherpesviridae and rainbow trout as a model salmonid host, which were infected with KHV by immersion. KHV was detected using direct methods (qPCR and semi-nested PCR) and indirect (enzyme-linked immunosorbant assay; ELISA, serum neutralization test; SNT). The non-koi herpesvirus disease (KHVD)-susceptible salmonid fish were demonstrated to transfer KHV to naive carp at two different temperatures including a temperature most suitable for the salmonid (15°C) and cyprinid (20°C). At 20°C KHVD was induced in carp cohabitated with infected trout. KHV was also detected virologically and serologically at the end of the experiment in both rainbow trout and carp.