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cyprinid herpesvirus 1 infection

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Datasheet

cyprinid herpesvirus 1 infection

Summary

  • Last modified
  • 12 July 2017
  • Datasheet Type(s)
  • Animal Disease
  • Preferred Scientific Name
  • cyprinid herpesvirus 1 infection
  • Pathogens
  • cyprinid herpesvirus 1
  • Overview
  • The cyprinid herpesvirus I (CHV) of common carp manifests itself in three clinical forms: chronic and benign epidermal proliferation or carp pox (CP), acute septicaemia in very young carp and dormant infection.

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Pictures

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PictureTitleCaptionCopyright
Herpesviral epidermal proliferation in carp (HEPC) or carp pox lesions in mirror-type common carp (Cyprinus carpio). Glistening patches of varying size, thickness and shape; some are translucent, others milky.
TitleHerpesvirus in carp
CaptionHerpesviral epidermal proliferation in carp (HEPC) or carp pox lesions in mirror-type common carp (Cyprinus carpio). Glistening patches of varying size, thickness and shape; some are translucent, others milky.
Copyright©N. Fijan
Herpesviral epidermal proliferation in carp (HEPC) or carp pox lesions in mirror-type common carp (Cyprinus carpio). Glistening patches of varying size, thickness and shape; some are translucent, others milky.
Herpesvirus in carpHerpesviral epidermal proliferation in carp (HEPC) or carp pox lesions in mirror-type common carp (Cyprinus carpio). Glistening patches of varying size, thickness and shape; some are translucent, others milky.©N. Fijan

Identity

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Preferred Scientific Name

  • cyprinid herpesvirus 1 infection

International Common Names

  • English: carp pox; epidermal hyperplasia; epidermal proliferation; epithelioma papulosum; epithelioma papulosum cyprini; fish pox; herpesviral epidermal proliferation in carp; herpesvirus septicaemia in carp; papillomatous skin growth

English acronym

  • CHI
  • CP
  • HEPC
  • HSC

Pathogen/s

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Overview

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The cyprinid herpesvirus I (CHV) of common carp manifests itself in three clinical forms: chronic and benign epidermal proliferation or carp pox (CP), acute septicaemia in very young carp and dormant infection.

Benign epithelial skin tumours (fish pox, CP, epithelioma papulosum cyprini, epithelioma papulosum, papillomatous skin growth, epidermal hyperplasia, epidermal proliferation) in carp were first reported in Europe in 1564 (Hofer, 1904). This disease and similar conditions in other fish were covered by the name pox or fish pox by Hofer (1904), Schäperclaus (1941), Nigrelli (1952) and Wolf (1988). A minority of authors used the term CP but extended the range of affected species (Ghittino, 1985; McAllister, 1993b).

The aetiology of CP was attributed to a herpesvirus by von Schubert (1964), who visualized its particles in epidermal proliferation by electron microscopy. Sano et al. (1985a,b) isolated CHV (or Herpesvirus cyprini) from common and coloured carp with CP. Experimental infection of 2-4 week-old fry with this virus induced an acute, generalized and species specific-infection with high mortality. Survivors developed typical CP lesions after several months (Sano et al., 1991). In accordance with the generally high host specificity of Herpesviridae, the CHV was not pathogenic to fry of two other cyprinids (Sano et al., 1991). Hedrick et al. (1990) confirmed the presence of herpesviruses in epidermal hyperplasia of coloured carp and their consistency with CHV, but did not report their isolation in cell culture.

‘Fish pox’ or CP is actually inappropriate for epidermal proliferation and, according to Nigrelli (1952), Hines et al. (1974) and Wolf (1983), it is not a true epithelioma or papilloma. All these terms should be used with caution or abandoned. The three postulated disease forms caused by CHV are referred to here as CHI. Herpesviral epidermal proliferation in carp (HEPC) is used instead of ‘pox’ and the systemic infection in fry is denoted as herpesvirus septicaemia in carp (HSC). The name ‘fish pox’ remains for similar, but aetiologically unclear epithelial skin proliferations in cyprinids and other fish.

The HEPC causes economic damage to carp farmers by reducing fish growth, rendering them unsightly and making them unmarketable. Although frequent in the past, HEPC is now rare in European and Israeli pond farming probably due to reduced inbreeding.

[Based upon material originally published in Woo PTK, Bruno DW, eds., 1999. Fish diseases and disorders, Vol. 3 Viral, bacterial and fungal infections. Wallingford, UK: CABI Publishing.]

Host Animals

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Animal nameContextLife stageSystem
Aristichthys nobilis (bighead carp)Aquatic: AdultEnclosed systems/Ponds
Cyprinidae
Cyprinus carpio (common carp)Domesticated hostAquatic: AdultEnclosed systems/Ponds

Hosts/Species Affected

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Herpesvirus epidermal proliferation in carp affects all scale-distribution and colour varieties of carp in Europe, Israel, Japan, South Korea, China and North America. Fry of goldfish (Carassius auratus), grass carp and willow shiner (Gnathopogon elongatus caerulescens) are resistant to CHV infection under controlled conditions and survivors remain free of skin neoplasms (Sano et al., 1991). Herpesvirus septicaemia in carp has yet not been diagnosed in farmed or feral populations.

Genetic predisposition seems to influence the appearance, frequency and severity of CP (Schäperclaus, 1941; Hines et al., 1974). Some inbred carp strains are particularly susceptible.

Distribution

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Herpesvirus epidermal proliferation in carp affects all scale-distribution and colour varieties of carp in Europe, Israel, Japan, South Korea, China and North America.

Distribution Table

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The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Continent/Country/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes

Sea Areas

Pacific, NorthwestPresentFijan, 1999

Asia

ChinaPresentFijan, 1999
IsraelPresentFijan, 1999
JapanPresentFijan, 1999
Korea, Republic ofPresentFijan, 1999

North America

USAPresentFijan, 1999

Diagnosis

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Herpesvirus epidermal proliferation in carp is a chronic and benign hyperplastic skin disease. Lesions may first develop on one or several locations, commonly on the fins. Initially they are flat, firm, smooth and translucent, but they soon grow thicker, giving the impression of paraffin drops on the skin. Multiple hyperplasia of squamous cells can form islands over the entire body. Further proliferation results in irregularly shaped papillomatous formations, several centimetres wide and 4-6 mm thick. These have a warty surface and a milky to greyish white colour, which is sometimes tinged with pink by capillary dilatation. Proliferations rarely coalesce to cover almost the whole skin. Some cells have cytoplasmic and Cowdry type A inclusions in nuclei, with marginated chromatin. The normal strata are lacking, the number of mucous cells is reduced and serous glands are absent. Mitoses are frequent. Proliferating cells are not invasive and they are not metastatic. The underlying structures appear normal in thin proliferations, but the subepidermis of large papillomatous lesions form finger-like projections to reach and nourish the thick and folded epithelium. Retarded growth and emaciation were consistently observed in advanced natural cases of ‘fish pox’. The tail of such a carp can be easily bent to touch its head. Such flabby fish have a reduced muscular tone and osteomalacia with very low levels of ash, calcium and phosphorus in the vertebrae (Mann, 1951). After recovery, some may have spinal deformities. The causal relationship of this disorder in metabolism of minerals and the CHV has not been established experimentally.

In 2 week-old fry infected experimentally by bath, HSC appeared after 1 week of incubation at 20°C (Sano et al., 1991). Mortality was over 80% in 2 week-old fry and about 30% in 4 week-old fish. In 8 week-old fingerlings, the infection did not cause mortality. At 15°C, mortality is highest and it decreases with increased temperatures to 20 and 25°C (Sano et al., 1993a). Sano et al. (1993b) showed that 2 week-old fry kept at 20°C did not develop HSC, and HEPC appeared 20 weeks after bath immersion. Clinical signs of HSC include loss of appetite, swimming in straight lines and occasional loss of movement. Fish have dark pigmentation, a distended belly, exophthalmia and haemorrhage on the operculum and abdomen. Infected 4 week-old fingerlings only exhibit spiral swimming. Necrosis is the main histological finding; it affects the liver, kidney and lamina propria of the intestinal mucosa. Papillomatous skin neoplasms develop in over 50% of survivors infected as fry-fingerlings and in about 10% of infected 1 or 2 year-old carp. Spontaneous outbreaks of HSC mortality have not been reported.

List of Symptoms/Signs

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SignLife StagesType
Finfish / Abnormal growth / s - Skin and Fins Aquatic:Adult Sign
Finfish / Cessation of feeding - Behavioural Signs Aquatic:Adult Sign
Finfish / Corkscrewing - Behavioural Signs Aquatic:Fry Sign
Finfish / Darkened coloration - Skin and Fins Aquatic:Adult Sign
Finfish / 'Dropsy' - distended abdomen, 'pot belly' appearance - Body Aquatic:Adult Sign
Finfish / Emaciation - Body Aquatic:Adult Sign
Finfish / Haemorrhagic lesions - Skin and Fins Aquatic:Adult Sign
Finfish / Intestines white-grey patches (haemorrhage / necrosis / tissue damage) - Organs Aquatic:Adult Sign
Finfish / Kidney - white-grey patches (haemorrhage / necrosis / tissue damage) - Organs Aquatic:Adult Sign
Finfish / Liver - white / grey patches (haemorrhage / necrosis / tissue damage) - Organs Aquatic:Adult Sign
Finfish / Mortalities -Miscellaneous Aquatic:Fry Sign
Finfish / Pop-eye - Eyes Aquatic:Adult Sign

Disease Course

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Cyprinid herpesvirus I-carp interactions were first described by Sano et al. (1991, 1993b). An IFAT demonstrated the virus in infected 2 week-old carp after 2-21 days in gills, liver, kidney, intestinal mucosa, oesophagus and lamina propria. Subsequently, virus could not be detected until the appearance of tumours, when it reappeared in skin (and in neoplastic tissue) but not in intestine. Search for the viral genome by in situ hybridization (Sano et al., 1993b) in asymptomatic fish 8-19 weeks after infection revealed its latent establishment in gills, cranial nerve ganglia, subcutaneous tissue and spinal nerves. The genome is associated with the induction and recurrence of HEPC.

There are no references about the specific immune response. Recurrence of infection indicates the absence of immunity.

Epidemiology

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The prevalence of HEPC on carp farms varies from less than 1:10,000 to over 70%. It appears during low to moderate temperatures from late winter to early summer. Skin tumours are transient - they usually desquamate after some time and scar tissue may develop. Hines et al. (1974) noted the disappearance of these lesions as the water warmed up during the summer. Under experimental conditions (Sano et al., 1993a) regression occurred after shifting the water temperature from 7.5°C to 20-30°C but not after the raise from 7.5 to 15°C. Sano et al. (1991) noted HEPC recurrence in experimentally infected carp after 7.5 months. Reappearance has long been known from pond environment (Schäperclaus, 1941). Young carp develop these tumours more rapidly than older ones (Sano et al., 1991). Herpesvirus epidermal proliferation in carp does not generally cause mortality.

Experimental transmission of ‘CP’ to common carp and common carp goldfish hybrids by cohabitation and by rubbing lesion tissue against abraded epithelium was reported by Sonstegard and Sonstegard (1978). After about 60 days at 10°C, HEPC developed. This incubation time was shorter than the ones reported by Sano et al. (1985ab, 1991).

Impact Summary

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CategoryImpact
Fisheries / aquaculture Negative

Impact: Economic

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The HEPC causes economic damage to carp farmers by reducing fish growth, rendering them unsightly and making them unmarketable. Although frequent in the past, HEPC is now rare in European and Israeli pond farming probably due to reduced inbreeding.

Zoonoses and Food Safety

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This species is not a zoonoses.

References

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Fijan N, 1999. Spring viraemia of carp and other viral diseases and agents of warm-water fish. Fish diseases and disorders. Volume 3: viral, bacterial and fungal infections., 177-244; 19 pp of ref.

Fijan N; Sulimanovic M; Bearzotti M; Muzinic M; Zwillenberg LO; Chilmonczyk S; Vautherot JF; de Kinkelin P, 1983. Some properties of the epithelioma papulosum cyprini (EPC) cell line from carp Cyprinus carpio. Annales de l’Institut Pasteur/Virologie, 134E:207-220.

Ghittino P, 1985. Technology and pathology in aquaculture. Vol. 2 - Pathology. Tecnologia e patologia in acquacoltura. Vol. 2 - Patologia., xi + 444 pp.

Ghittino P; Beccaria E; Masoero L; Rosso A, 1984. Aggiornamento sul cosi detto variolo dei ciprinidi. Rivista Italiana di Piscicoltura e Ittiopatologia, 19:115-120.

Grützner L, 1956. Überprüfung einiger Anwendungsmöglichkeiten der Gewebekultur von Lebistes reticulatus (Peters) und Macropodus opercularis (Linne) in der Virusforschung. Zentralblatt für Bakteriologie, 165 I (Orig):81-96.

Hedrick RP; Groff JM; Okihiro MS; McDowell TS, 1990. Herpesviruses detected in papillomatous skin growths of koi carp (Cyprinus carpio). Journal of Wildlife Diseases, 26(4):578-581.

Hines RS; Wohlfarth GW; Moav R; Hulata G, 1974. Genetic differences in susceptibility to two diseases among strains of the common carp. Aquaculture, 3:187-197.

Hofer B, 1904. Handbuch der Fischkrankheiten. Verlag der Allgemeinen Fischerei-Zeitung. Munich, Germany: B.Heller.

Jiang Y; Ahne W; Jørgensen PEV, 1994. Comparison of the characteristics of four aquareovirus isolated from fish in P. R. China. In: Program and Abstracts, International Symposium on Aquatic Animal Health. P1. Davis, California, USA: University of California, School of Veterinary Medicine.

Mann H, 1951. Chemische Untersuchungen über Knochenweiche beim Karpfen. Archiv für Fischereiwissenschaften, 3:105-113.

McAllister PE, 1993. Goldfish, koi, and carp viruses. In: Stoskopf MK, ed. Fish Medicine. Philadelphia, USA: Saunders WB, 478-486.

McAllister PE; Lidgerding BC; Herman RL; Hoyer LC; Hankins J, 1985. Viral diseases of fish: first report of carp pox in golden ide (Leuciscus idus) in North America. Journal of Wildlife Diseases, 21(3):199-204.

Nigrelli RF, 1952. Viruses and tumors of fishes. Annals of the New York Academy of Sciences, 54:1076-1092.

Sano N; Moriwake M; Hondo R; Sano T, 1993. Herpesvirus cyprini: a search for viral genome in infected fish by in situ hybridization. Journal of Fish Diseases, 16(5):495-499.

Sano N; Moriwake M; Sano T, 1993. Herpesvirus cyprini: thermal effects on pathogenicity and oncogenicity. Gyobyo Kenkyu = Fish Pathology, 28(4):171-175.

Sano T; Fukuda H; Furukawa M, 1985. Herpesvirus cyprini: biological and oncogenic properties. Fish Pathology, 20(2/3):381-388.

Sano T; Fukuda H; Furukawa M; Hosoya H; Moriya Y, 1985. A herpesvirus isolated from carp papilloma in Japan. Fish and shellfish pathology. Proceedings of the European Association of Fish Pathologists, Plymouth, September 1983., 307-311.

Sano T; Morita N; Shima N; Akimoto M, 1991. Herpesvirus cyprini: lethality and oncogenicity. Journal of Fish Diseases, 14(5):533-543.

Schaperclaus W; Kulow H; Schreckenbach K, 1979. Fish diseases. Fischkrankheiten., 4th edition:xv + 1089pp.; [479 fig., Bibliography pp.944-1060, 170 X 240 X 65 mm].

Schäperclaus W, 1941. Fischkrankheiten, 2nd edition. Gustav Wenzel & Sohn, Braunschweig.

Sonstegard RA; Sonstegard KS, 1978. Herpesvirus-associated epidermal hyperplasia in fish (carp). In: de-The G, Henle W, Rapp F, eds. Proceedings of the International Symposium on Oncogenesis and Herpesviruses III. International Agency for Research on Cancer, Scientific Publication 24, Lyons, France, 863-868.

von Schubert G, 1964. Elektronenmikroskopische Untersuchungen zur Pockenkrankheit des Karpfens. Zeitschrift für Naturforschung, 19:675-682.

Wolf K, 1983. Biology and properties of fish and reptilian herpesviruses. In: Roizman B, ed. The Herpesviruses, Vol 2. New York, USA: Plenum Press, 319-366.

Wolf K, 1988. Fish viruses and fish viral diseases. Fish viruses and fish viral diseases., xii + 476 pp.

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