Host Range of Carp Edema Virus (CEV) during a Natural Mortality Event in a Minnesota Lake and Update of CEV Associated Mortality Events in the USA

Abstract

Mass mortality events of common carp (Cyprinus carpio, carp) associated with carp edema virus (CEV) alone or in coinfections with koi herpesvirus (KHV), is an emerging issue. Despite recent outbreaks of CEV in wild carp populations, the host range of North American species has not been well studied. To that end, we intensively sampled carp (n = 106) and co-habiting native fish species (n = 5 species; n = 156 total fish) from a CEV-suspect mass-mortality event of carp in a small Minnesota lake (Lake Swartout). Additionally, fecal and regurgitant samples (n = 73 each) from double-crested cormorants (Phalacrocorax auritus, DCCO) were sampled to test the potential of DCCO to act as a vector for virus transmission. CEV was confirmed to be widespread in the Lake Swartout carp population during the outbreak with high viral loads and histological confirmation, suggesting that CEV was the cause of the mortality event. There were no detections of CEV in any native fish species; however, DCCO regurgitant and fecal samples were positive for CEV DNA. In addition, three CEV-positive and one CEV + KHV-positive mortality events were confirmed with no observed mortality or morbidity of non-carp species in other lakes. This study provides evidence that CEV infection and disease may be specific to carp during mortality events with mixed-species populations, identifies DCCO as a potential vector for CEV, and further expands the known range of CEV, as well as coinfections with KHV, in North America.

A natural outbreak of infectious spleen and kidney necrosis virus threatens wild pearlspot, Etroplus suratensis in Peechi Dam in the Western Ghats biodiversity hotspot, India

“…The Peechi dam comes under the premises of Peechi‐Vazhani wildlife sanctuary in the Western Ghats., which is considered as one of the regions harbouring the richest biodiversity in the world. Recently, virus‐associated mortality events were reported for CEV in wild carps from natural and artificial lakes in the United States and Italy, respectively (Marsella et al., 2021; Tolo et al., 2021). A fish viral disease outbreak in this sensitive region may therefore lead to irreversible biodiversity losses among the endemic wild fish population.…”

It is everywhere—A survey on the presence of carp edema virus in carp populations in Germany

“…In this earlier study, either no or very low levels of CEV‐specific DNA (Cq levels of 34 to 43) were detected in gill samples as well (Matras et al., 2019). In addition, CEV‐ specific DNA could not be detected in gill samples from different fish species from a natural lake in Minnesota, USA where CEV‐related mortality in carp was observed (Tolo et al., 2021). CEV DNA also could not be detected in gill samples of invasive round goby ( Neobobius melanostomus ) from various locations in Poland and Germany (Jin et al., 2020).…”

A cell line derived from heart of rainbow trout is refractory to Tilapia lake virus

“…Subsequently, several fish cell lines were developed from different fish tissues, such as gills, fin, swim bladder, ovary, heart, spleen, muscle, skin, and so forth. Thangaraj Fish cell lines have emerged as vital resource for various applications, like in virus isolation/propagation and studying the biology of viruses infecting fish (Dixon et al, 2016;Liu et al, 2020;Manríquez et al, 2017;Matvienko et al, 2014;Pham et al, 2020;Tolo et al, 2021;Xu et al, 2021;Zeng et al, 2022), synthesis of therapeutic fish proteins, gene expression, and toxicological research (Goswami et al, 2014;Kalman et al, 2019;Segner, 2004;Tan & Schirmer, 2017;Villena, 2003), detecting toxic effects of certain compounds (Segner, 2004;Tan & Schirmer, 2017), biomedical research (Lin et al, 2016;Lleras-Forero et al, 2020;Metz et al, 2012), gene transfer, expression and regulation (Iyengar et al, 1996), and so forth. They are frequently employed in virological experiments, since viruses multiply only in living cells of specific hosts .…”