Carp edema virus and immune response in carp (Cyprinuscarpio): Current knowledge

Abstract

Common carp (Cyprinus carpio) is one of the most economically valuable freshwater fish worldwide. The majority of global production of common carp is destined for human consumption, but members of its ornamental variety, koi carp, are also raised for decorative purposes. According to annual statistics of FAO (Food and Agriculture Organization of the United Nations), fishery and aquaculture production of common carp accounted for more than 7.5% of the global freshwater fish production in 2018. More specifically, more than 4.3 million tons of carp were caught or bred in 2018 with a steady yearly increase (FAO, 2020). The importance of common carp is even greater in Europe, where it accounted for over 30% of the freshwater fish production in 2018 (FAO, 2020). Historically, chronicles depict domestication of common carp in China centuries before domestication in Europe, but it is possible that the domestication occurred independently in both places (Balon, 1995; Vilizzi, 2012). Viral diseases are one of the most relevant causes of a decrease in aquaculture production, either through significant reduction of their growth rate or by direct mortalities of the host fish. Among numerous carp viral diseases, three diseases seem to be most important as they cause extensive damage to carp aquaculture. Carp edema virus (CEV) together with cyprinid herpesvirus 3 (koi herpesvirus, CyHV-3, KHV) and carp sprivivirus (spring viraemia of carp virus, SVCV) are infectious viruses causing disease and major losses in common carp populations and carp varieties around the world. Out of these three, only SVCV affects a broad number of the Cyprinidae family members, causing spring viraemia of carp (SVC) (Hoole et al., 2001).

Carp Edema Virus Disease in Serbia - Disease Out of Control

“…Th e clinical signs and lesions observed in carp during the disease episodes in Serbia were consistent with previous reports (Way & Stone 2013;Lewisch et al 2015;Machat et al 2021). Th e prominent clinical signs present during CEVD episodes in all the cases reported here are increased gill and skin mucous production with gill edema.…”

“…In 17 outbreaks, co-infection with bacteria or fungi was present, as reported by other authors (Way et al 2017;Machat et al 2021). Th ese isolated bacteria and fungi are known to be opportunistic pathogens for carp, and they had probably contributed to increase the severity of the disease.…”

“…However, the occurrence and spread of a new disease which may signifi cantly aff ect the health of carp is a disturbing fact which requires attention of all the parties involved in the production chain. Carp edema virus disease (CEVD) is an emerging disease considered to be a potential risk for the carp aquaculture and for global food security as well (Kurita et al 2009; Way et al 2017), with new data about its spread, economic and biological properties being published rapidly over the past few years (Rehman et al 2020; Machat et al 2021).…”

“…Th e most frequently observed external lesions consist of increased skin mucous production, enophthalmos, erosion or hemorrhages at the base of the fi n and gill necrosis (Way et al 2017). Gross lesions in gills (hypertrophy, hyperplasia and lamellae clubbing) and subsequent necrosis of secondary gill lamellae may lead to the death of the infected fi sh (Machat et al 2021).…”

Characteristics of pathology and transcriptome profiling reveal features of immune response of acutely infected and asymptomatic infected of carp edema virus in Koi

“…Common carp is one of the most economically valuable freshwater fish in global aquaculture according to annual statistics of FAO (Food and Agriculture Organization of the United Nations). The majority of global production of common carp is destined for human consumption, but its ornamental variety, Koi carp, were also considered among most popular ornamental species of fish (1). Intensive culture and international trade of common carp have led to the global spread of virus pathogens of carp, including Koi herpesvirus (KHV), carp edema virus (CEV) and Spring Viraemia of Carp Virus (SVCV) (2)(3)(4).…”