Koi herpesvirusno oboljenje šarana

Abstract

Oboljenje koi šarana (Cyprinus carpio koi) i običnog šarana (Cyprinus carpio carpio), izazvano herpes virusom, praćeno visokim mortalitetom, od 1998. godine je zahvatilo mnoge ribnjake širom sveta, izazivajući masovna uginuća i značajne finansijske gubitke. Virus nalik herpes virusima, nazvan koi herpesvirus (KHV) izolovan je i identifikovan iz koi i običnog šarana tokom pojavljivanja masovnih uginuća. Prva pojava bolesti sa visokim mortalitetom običnog i koi šarana izazvana koi herpesvirusom (KHV) opisana je 1998. godine u Izraelu i SAD. Od tada je potvrđen veći broj slučajeva izbijanja ovog oboljenja širom sveta, uključujući SAD, Izrael i veliki broj evropskih zemalja. Uginuća su se javljala sezonski, krajem proleća i početkom jeseni, kada je temperatura vode od 18 do 28oC. Najznačajniji faktor spoljašnje sredine koji utiče na pojavu i težinu bolesti je temperatura vode. Trenutno se ovo oboljenje smatra jednim od činilaca koji predstavlja najveću opasnost za populacije običnog i koi šarana. Obolele ribe su dezorijentisane, nekoordinisanih pokreta, ubrzanog disanja, otečenih škrga i sa lokalnim kožnim lezijama. Virus je izolovan iz tkiva obolelih riba i kultivisan na KF- 1 (koi fin cells) ćelijskoj liniji. Elektronskom mikroskopijom su uočene virusne čestice identične virusima iz familije Herpesviridae. Analizom polipeptida viriona i DNK utvrđene su razlike između KHV i ranije poznatih herpes virusa ciprinida, Herpesvirus cyprini (CHV) i virusa kanalskog somića (Channel catfish virus - CCV). U 2004. i 2005. godini utvrđen je visok mortalitet jednogodišnje i dvogodišnje mlađi šarana na tri ribnjaka. Na dva ribnjaka uginuće se javljalo kod jednogodišnje i dvogodišnje mlađi šarana u prolećnom periodu, kada je temperatura vode bila viša od 18oC. U jesenjem periodu javilo se uginuće jednogodišnje mlađi šarana pri temperaturi vode višoj od 23oC. Na osnovu utvrđenih patomorfoloških promena i visokog mortaliteta u periodu godine kada je temperatura bila viša od 18oC, sumnja se da je KHV prisutan i na ribnjacima u Srbiji, iako virus nije izolovan. Cilj ovog rada je da ukratko prikaže relevantne podatke o ovom oboljenju koje nanosi značajne gubitke proizvodnji šarana, trenutnu rasprostranjenost oboljenja, dijagnostičke metode i mogućnosti prevencije i kontrole KHV.

A disease in the koi carp (Cyprinus carpio koi) and the common carp (Cyprinus carpio carpio), caused by the herpesvirus and accompanied by a high mortality rate, has spread across numerous fish ponds all over the world since 1998, resulting in massive mortality and significant financial losses. The herpesvirus-like virus, called the koi herpesvirus (KHV) has been isolated and identified from the koi and the common carp in the course of the incidences of massive mortalities. The first appearance of a disease with a high mortality in the common and the koi carp caused by the koi herpesvirus (KHV) was described in 1998 in Israel and the United States of America (USA). Since that time, a large number of cases of outbreaks of this disease have been confirmed throughout the world, including the USA, Israel, and a large number of European countries. The deaths occurred seasonally, in late spring or early autumn, when the water temperature was from 18-28ºC. The most important factor of the environment that affects the occurrence and gravity of this disease is the water temperature. This disease is currently considered one of the factors that present the biggest threat to populations of the common and the koi carp. Diseased fish are disoriented, their movements uncoordinated, their breathing rapid, gills swollen, and they have local skin lesions. The virus was isolated from tissue of diseased fish and cultivated on a KF-1 (koi fin cells) cell line. Electronic microscopy examinations revealed virus identical viral particles of the Herpesviridae family. Analyses of the virion polypeptide and DNA established differences between the KHV and the previously known herpesvirus of the Cyprinida family, Herpesvirus cyprini (CHV), and the virus of the channel catfish (Channel catfish virus - CCV). In the years 2004 and 2005, high mortality was established among one-year and two-year carp fry on three fish ponds. At two ponds, the deaths occurred among one year and two-year carp fry during the spring period, when the water temperature was over 18ºC. During the autumn period, mortality was recorded among one-year carp fry at water temperatures above 23ºC. On the grounds of the determined pathomorphological changes and the high mortality during the period of the year when the temperature was above 18ºC, we suspect that KHV is also present in fish ponds in Serbia, even though the virus itself has not been isolated. The objective of this work is briefly to present the relevant data on this disease which is inflicting significant losses to carp production, to show the current distribution of this disease, the diagnostic methods, and the possibilities for the prevention and control of KHV.