VHSV in the Great Lakes

Transcription

1 VHSV in the Great Lakes VHSV Mortality Events 2005 Rod Getchell Aquatic Animal Health Program Department of Microbiology and Immunology College of Veterinary Medicine Cornell University VHSV - Sequence data VHSV - Genotypes A region of the G gene was sequenced at the USGS Seattle Laboratory. VHSV isolates from the Lake Ontario freshwater drum, the Lake St. Clair muskellunge, and the round goby were found to be essentially identical. Significantly different from other North American VHSV isolates. JP99Obama25 WA91Clearwater 83 BC99292 BC ME03 USMakah BC99001 BC99010 BC93372 MI03Muskellunge 100 JP96KRRV DK6p403 DKMrhabdo 75 NOA16368G FIka FR DK7380 DKHededam 100 DKF1 100 DK5131 DK2835 GE12 96 UKMLA986P DK4p101 FRL59X UK86094 DK1P53 DK1P substitutions/site Elsayed et al. IVa IVb Ib Id Ia I I Ic Ie III II Genotype I Europe, Japan Genotype II Genotype III Europe, Japan Genotype III Genotypes I & II Europe, Japan Uploads/Documents/AAAH06MarineVHSV.pdf Genotype IV IVa North America, Japan, Korea (marine) IVb North America, Great Lakes (freshwater), eastern Canada (marine) Disease Investigations Surveillance Efforts Disease Investigations - April, Lake St. Clair Ontario (U of Guelph) FW Drum, Musky Acute Mortality April, 26, Sandusky Bay, Lake Erie Ohio (USFWS, LaCrosse, WI) FW Drum VERY LARGE mortality event NYSDEC 1

2 How bad can it get? How bad can it get? Freshwater Drum mortality in Lake Erie Investigated by USFWS, LaCrosse, WI Millions of pounds of FW Drum Windrows of fish along the beach piled up 10 wide and 4 high Severity will likely depend on environmental conditions stressors We will probably see the New Pathogen and Naive Host scenario for several years. research.html Photo: Dr. James Winton, USGS Disease Investigations - May 3, May 12, May 15, May 22, May 24, May 31, Cape Vincent, St. Lawrence River Clayton, St. Lawrence River Sandy Creek, L. Ontario Middle Basin, Lake Erie Clayton, St. Lawrence River Middle Basin, Lake Erie Ohio (USFWS, LaCrosse, WI) Ohio (USFWS, LaCrosse, WI) Round Goby Burbot Round Goby Yellow Perch Muskellunge YP, WAL, WhB, FW Drum, SMB Large mortality event Continuing mortality, multiple spp. Large mortality event Large Mortality event Multiple large fish found dead Large mortality event Disease Investigations - June, June 1, June 8, Clinton River, Lake St. Clair Western Basin, Lake Erie Tibbett s Point, Lake Ontario Michigan (Michigan State University) Ohio (USFWS, LaCrosse, WI) Gizzard shad, Redhorse Sucker, Bluntnose Minnow, N. Pike Yellow Perch, White Bass Smallmouth Bass Large mortality event Mortality event Continuing mortality event; multiple spp. Disease Investigations - August 18, Conesus Lake Walleye Mortality Event VHSV Mortality Events 2

3 VHSV Gross Pathology Causes a hemorrhagic disease VHSV - isolations Round Goby St. Lawrence River and Lake Ontario BioMar Multiplies in endothelial cells of blood capillaries, leucocytes, hematopoietic and nephron cells Muskellunge (57, 45 lbs) St. Lawrence River VHSV - isolations VHSV - isolations Smallmouth Bass Sodus Bay, Lake Ontario Burbot St. Lawrence River Walleye Conesus Lake Diagnostic Approach Surveillance OIE and Blue Book of the FHS/AFS Cell Culture RT-PCR New Test Quantitative RT-PCR (qrt-pcr) Cell Culture & RT-PCR Tissue samples are homogenized and cultured preferably on EPC cell lines (Epithelioma Papulosum cyprini from carp Cyprinus carpio). Can also use Fathead Minnow (FHM) or Bluegill Fry cells Observe cells for cytopathic effects for at least 2 weeks If CPE is seen, confirm by at least 2 subsequent passages Cells can appear as rounded up with a granular appearance Viral identity confirmed using RT-PCR and sequencing Negative control FHM cells CPE in FHM cells 4 days after inoculation 3

4 Surveillance Efforts - Collaboration with: State Department of Environmental Conservation Cornell University Biological Field Station, Oneida Lake, SUNY College of Environmental Sciences and Forestry Syracuse, Thousand Island Biological Field Station, St. Lawrence River Surveillance Samples - NYS DEC Bait Minnow surveys (Lake Erie, Niagara River, Saint Lawrence River) NYS DEC Priority Waters and spp.(17 waters) NYS DEC Priority Fish Species TOTAL = fish St. Lawrence River fish survey (288 fish, TIBS) State VHSV Surveillance Priorities identified by NYS DEC Priority waters 30 of a predator fish species 30 of a prey fish species Priority fish species Chinook Salmon Coho Salmon Walleye Bait Minnows State Surveillance From: Surveillance Samples Cell Culture Positive St. Lawrence River Bluegill Rock Bass Black Crappie Pumpkinseed Smallmouth Bass Largemouth Bass Lake Ontario Freshwater Drum Niagara River Emerald Shiner Lake Erie Emerald Shiner Northern Pike White Perch Brown Bullhead Channel Catfish Yellow Perch Bluntnose Minnow Mortalities: Round Gobies Walleyes Muskellunge Burbot Gizzard Shad Smallmouth Bass Results up to date: 15 Apr 19 Different Fish Species State Surveillance positive by cell culture From: 4

5 State Mortalities and Surveillance State & Mortalities and Surveillance From: From: May Freshwater Drum Little Lake Butte des Morts Source: Michigan May, Budd Lake Mortalities in: Black Crappie Bluegill Muskellunge Source: 5

6 QuickTime and a TIFF (LZW) decompressor are needed to see this picture. May, Lake Michigan Lake Whitefish Door County, WI Smallmouth Bass Sturgeon Bay, WI Brown Trout near Algoma, WI Source: VHSV Cell Culture Isolation and Confirmation VHSV Bluegill Rock Bass Black Crappie Pumpkinseed Smallmouth Bass Largemouth Bass Muskellunge Northern Pike Walleye Yellow Perch Redhorse Sucker White Sucker Chinook Salmon Brown Trout Lake Trout Rainbow Trout Channel Catfish Brown Bullhead White Perch White Bass Emerald Shiner Bluntnose Minnow Freshwater Drum Round Goby Lake Whitefish Gizzard Shad Burbot Carp VHSV VHSV 2005,, 6

7 Great Lakes VHSV Where did it come from? Great Lakes Genotype IVb is not closely related to the European or Japanese Genotypes I, II, or III Great Lakes Genotype IVb is most closely related to Genotype IVa It probably originated from a marine fish off the Atlantic coast of North America Presence/Absence of Signs of Disease Fish Mortalities Some with hemorrhagic lesions Some without hemorrhagic lesions Presence/Absence of Signs of Disease Fish Mortalities Some with hemorrhagic lesions Some without hemorrhagic lesions Surveillance Samples No remarkable lesions No Viral Copy Number Low Viral Copy Number Very High Viral Number Grossly Visible Signs of Disease Variable May vary by species May vary by viral isolate (potential for mutations) May vary by environmental stressors present Great Lakes VHSV How long has it been here? Great Lakes Genotype IVb : Approx. 20 isolates have been partially sequenced (J. Winton, USGS, Seattle, WA) All are virtually identical based on G gene This tells us it is a relatively new introduction Great Lakes VHSV How did it get into the Great Lakes ecosystem? Possibilities By movement of an infected fish By various non-human animal activities (mammals, birds, reptiles, amphibians) By human intervention Sport fishing (bait minnows, contaminated fishing equipment, contaminated live well water, ad hoc fish stocking ) Boating Other water recreational activities Ballast water Basically We don t know how it got here 7

8 What now? Restrictions in movement of live fish Federal Order Various state regulations Health testing of fish Actions to avoid movement of the virus Everyone will have a part to play and everyone will have to do their part What now? Restrictions in movement of live fish Health testing of fish Actions to avoid movement of the virus Will involve changes in the way we do things Aquaculturists Sport fishery managers Scientific community General public Future Needs Continued Surveillance Research Public Education Future Needs Continued Surveillance Research Public Education What is on the Horizon??? Art by Jean Gawalt Art by Jean Gawalt Spring Viremia of Carp Virus Thanks to: Fish Pathology: Dr. Paul Bowser, PhD Professor of Aquatic Animal Medicine Dr. Geof Groocock, DVM Extension Associate Greg Wooster, MSc Research Support Specialist Steve Frattini NIH Student Fellow Kelly Britt Aquavet Student Intern Holly Kohler Sarah McConnachie Virology: Dr. James Casey, PhD Professor of Virology Dr. Young-Sook Kim, PhD Visiting Scientist Rufina Casey, MSc Research Support Specialist Pathology: Dr. Ana Alcaraz, DVM, PhD, DACVP 8

9 Thanks to: USGS: Dr. Jim Winton Dr. Bill Batts NYS DEC Doug Stang Bill Culligan Andy Noyes Regional Chiefs and Staff SUNY ESF Dr. John Farrell Geof Eckerland USDA-APHIS Dr. Jill Rolland Dr. Gary Egrie Janet Warg Danish Institute for Food and Veterinary Research, Dr. N.J. Olesen Department of Environmental Conservation United States Department of Agriculture Animal and Plant Health Inspection Service 9