Herpesvirus anguillae (HVA) isolations from disease outbreaks in cultured European eel, Anguilla anguilla in the Netherlands since 1996

Abstract Since 1996, Herpesvirus anguillae (HVA) infections were diagnosed 19 times at 14 Dutch eelfarms with European eels ( Anguilla anguilla ). The eels showed various clinical symptoms, butpredominantly apathy, haemorrhages in their skin and fins, ulcerative skin and fin lesions, haem-orrhages in the gills, congested gill epithelium, a pale liver, and a mortality up to 10%. Eel gillswere in more cases HVA positive than the corresponding organs. Therefore, gills should be sam-pled for HVA-isolations in diseased eels. Often a bad water quality induced the virus propaga-tion. Eleven outbreaks occurred at water temperatures higher than 23°C; six outbreaks at watertemperatures lower than 23°C. Decreasing the temperature to below 22°C worked well in 4 cases.The agent was isolated on Eel Kidney (EK-1) cells, and characterized as a herpesvirus with elec-tron microscopy, typed by digestion of virus DNA with restriction enzyme Hind III, and its DNAfragments were analysed by gel electrophoresis. All Dutch HVA isolates showed a similar DNApattern. Comparison of the DNA of the Dutch viruses and Japanese isolates revealed a smalldifference after digestion with

[1]  O. Haenen,et al.  Persistence of herpesvirus of eel Herpesvirus anguillae in farmed European eel Anguilla anguilla. , 2001, Diseases of aquatic organisms.

[2]  A. Eldar,et al.  A Herpesvirus Associated with Mass Mortality of Juvenile and Adult Koi, a Strain of Common Carp. , 2000, Journal of aquatic animal health.

[3]  G. Charlier,et al.  Isolation of virus-like particles from koi (Cyprinus carpio) suffering gill necrosis. , 2000 .

[4]  T. Miyazaki,et al.  Gill filament necrosis in farmed Japanese eels, Anguilla japonica (Temminck & Schlegel), infected with Herpesvirus anguillae , 1999 .

[5]  U. Truyen,et al.  Mass mortalities in Koi carp, Cyprinus carpio, associated with gill and skin disease , 1999 .

[6]  F. Wagenaar,et al.  First isolation of herpesvirus of eel (Herpesvirus anguillae) in diseased European eel (Anguilla anguilla L.) in Europe , 1999 .

[7]  T. Miyazaki,et al.  Characterization and Pathogenicity of a Herpesvirus Isolated from Cutaneous Lesion in Japanese Eel, Anguilla japonica , 1997 .

[8]  G. Kou,et al.  Biological and serological comparisons of eel herpesvirus in Formosa (EHVF) and Herpesvirus anguillae (HVA) , 1996 .

[9]  Europe.,et al.  In Europe … , 1994, Current History.

[10]  M. Yoshimizu,et al.  Role of Viruses in the induction of skin tumours and tumour-like proliferations of fish , 1994 .

[11]  J. Castric,et al.  The occurrence of virus infections in elvers and eels (Anguilla anguilla) in europe with particular reference to VHSV and IHNV , 1994 .

[12]  R. Hedrick,et al.  New viruses described in finfish from 1988–1992 , 1993, Annual Review of Fish Diseases.

[13]  G. Barrow,et al.  Cowan and Steel's Manual for the identification of medical bacteria: Foreword , 1993 .

[14]  G. Kou,et al.  Characterization of A Herpes-like Virus Isolated from Cultured Japanese Eels in Taiwan , 1992 .

[15]  S. Yun,et al.  Isolation of an epitheliotropic herpesvirus from white sturgeon acipenser transmontanus , 1991 .

[16]  M. Sano,et al.  ISOLATION AND CHARACTERIZATION OF A NEW HERPESVIRUS FROM EEL , 1990 .

[17]  G. Csaba,et al.  Demonstration of herpesvirus like particles in skin lesions of European eel (Anguilla anguilla) , 1986 .

[18]  T. Yamamoto,et al.  Characterization of Herpes virus vitreum isolated from hyperplastic epidermal tissue of walleye, Stizostedion vitreum vitreum (Mitchill)* , 1983 .

[19]  H. Fukuda,et al.  Yamame tumor virus: lethality and oncogenicity. , 1983 .

[20]  M. Yoshimizu,et al.  Studies on a New Virus (OMV) from Oncorhynchus masou. II, Oncogenic Nature , 1981 .

[21]  G. Hayward,et al.  Anatomy of herpes simplex virus DNA: strain differences and heterogeneity in the locations of restriction endonuclease cleavage sites. , 1975, Proceedings of the National Academy of Sciences of the United States of America.

[22]  N. Fijan.  Progress report on acute mortality of channel catfish fingerlings caused by a virus. , 1968, Bulletin - Office international des epizooties.

[23]  S. T. Cowan,et al.  Manual for the identification of medical bacteria. , 1960 .