Distribution of an Invasive Aquatic Pathogen (Viral Hemorrhagic Septicemia Virus) in the Great Lakes and Its Relationship to Shipping

Abstract

Viral hemorrhagic septicemia virus (VHSV) is a rhabdovirus found in fish from oceans of the northern hemisphere and freshwaters of Europe. It has caused extensive losses of cultured and wild fish and has become established in the North American Great Lakes. Large die-offs of wild fish in the Great Lakes due to VHSV have alarmed the public and provoked government attention on the introduction and spread of aquatic animal pathogens in freshwaters. We investigated the relations between VHSV dispersion and shipping and boating activity in the Great Lakes by sampling fish and water at sites that were commercial shipping harbors, recreational boating centers, and open shorelines. Fish and water samples were individually analyzed for VHSV using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and cell culture assays. Of 1,221 fish of 17 species, 55 were VHSV positive with highly varied qRT-PCR titers (1 to 5,950,000 N gene copies). The detections of VHSV in fish and water samples were closely associated and the virus was detected in 21 of 30 sites sampled. The occurrence of VHSV was not related to type of site or shipping related invasion hotspots. Our results indicate that VHSV is widely dispersed in the Great Lakes and is both an enzootic and epizootic pathogen. We demonstrate that pathogen distribution information could be developed quickly and is clearly needed for aquatic ecosystem conservation, management of affected populations, and informed regulation of the worldwide trade of aquatic organisms.

Real-time polymerase chain reaction assays for the detection and quantification of Edwardsiella tarda, Edwardsiella piscicida, and Edwardsiella piscicida–like species in catfish tissues and pond water

“…23 Assays have been developed for the detection and quantification of a wide array of viral, parasitic, and bacterial fish pathogens in both fish tissues and the environment. 3,11,19,27 In catfish aquaculture, several assays have been developed for the detection and quantification of pathogens in the pond environment. [9][10][11] All 3 assays used in the current study were able to detect target DNA in both clinically and subclinically infected fish.…”

Smartphones Reveal Angler Behavior: A Case Study of a Popular Mobile Fishing Application in Alberta, Canada

“…These phenomena are increasing in both scale and frequency (MacIsaac et al 2004;Bain et al 2010) and can be important to sustainable fisheries management (Dextrase and Mandrak 2006;Faisal et al 2012). Apps allow for rapid reporting and detection (e.g., MISIN 2014) and have the added benefit of generating movement data that reveal transmission pathways and trends, and ultimately inform prevention and response efforts.…”

Temporal Variation in Viral Hemorrhagic Septicemia Virus Antibodies in Freshwater Drum (Aplodinotus grunniens) Indicates Cyclic Transmission in Lake Winnebago, Wisconsin

“…The source of VHSV introduction into the Great Lakes Basin remains unclear, but ship ballast water discharge, contaminated live well water from recreational boating, and shedding of virus by migratory fish have been implicated (15,16). Surveys using tissue culture and real-time reverse transcription (rRT)-PCR indicate that VHSV is widely dispersed throughout the Laurentian Great Lakes (17) and could have spread through multiple routes (5,14,15,18).…”

“…Surveys using tissue culture and real-time reverse transcription (rRT)-PCR indicate that VHSV is widely dispersed throughout the Laurentian Great Lakes (17) and could have spread through multiple routes (5,14,15,18). The introduction of VHSV and potential economic impacts associated with the spread of the virus led to increased surveillance in Wisconsin and other states within the Great Lakes Basin.…”