Comparative susceptibility of Arctic char (Salvelinus alpinus), rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta) to the Scottish isolate of infectious salmon anaemia virus

Experimental infection studies were conducted to determine the susceptibili ty of pathogen-free Arctic char (Salvelinus alpinus), rainbow trout (Oncorh ynchus mykiss) and brown trout (Salmo trutta) to the Scottish isolate of in fectious salmon anaemia virus (ISAV). No mortalities were recorded in any o f these species following infection by intra-peritoneal injection, although transient drops in haematocrit were recorded. Sub-samples of all species w ere screened for the presence of ISAV using RT-PCR and virus culture. While virus was unculturable from all samples at 40 days post-infection, virus w as detectable using RT-PCR in all species. Clearance of virus following exp erimental infection did however progress at a greater rate in Arctic char t han in rainbow trout and brown trout. The potential for this species to act as a long-term carrier of ISAV, and thus exert a role in the epizootiology of ISAV in Scotland may be less than in other salmonid species. The increa sing commercial production of Arctic char render these findings significant to the future management of ISAV in Scotland. (C) 2001 Elsevier Science B. V. All rights reserved.