West Nile Virus April 2003 Emi Kate Saito, VMD, MSPH National Wildlife Health Center Madison, WI 1

Emi Kate Saito 1993: BS – Zoology and Biological Aspects of Conservation, Univ. of Wisconsin-Madison1993: BS – Zoology and Biological Aspects of Conservation, Univ. of Wisconsin-Madison 1997: VMD – Veterinary Medicine, Univ. of Penn.1997: VMD – Veterinary Medicine, Univ. of Penn Dept. of Biology, Emory University Graduate School (Population Biology, Ecology and Evolution) Dept. of Biology, Emory University Graduate School (Population Biology, Ecology and Evolution) – Small animal Practice, Atlanta & Annapolis – Small animal Practice, Atlanta & Annapolis MSPH- Epidemiology, Emory University MSPH- Epidemiology, Emory University 2001 WNV Season: DeKalb Co. Board of Health, Atlanta GA2001 WNV Season: DeKalb Co. Board of Health, Atlanta GA 2002: USGS NWHC2002: USGS NWHC : BS – Zoology and Biological Aspects of Conservation, Univ. of Wisconsin-Madison1993: BS – Zoology and Biological Aspects of Conservation, Univ. of Wisconsin-Madison 1997: VMD – Veterinary Medicine, Univ. of Penn.1997: VMD – Veterinary Medicine, Univ. of Penn Dept. of Biology, Emory University Graduate School (Population Biology, Ecology and Evolution) Dept. of Biology, Emory University Graduate School (Population Biology, Ecology and Evolution) – Small animal Practice, Atlanta & Annapolis – Small animal Practice, Atlanta & Annapolis MSPH- Epidemiology, Emory University MSPH- Epidemiology, Emory University 2001 WNV Season: DeKalb Co. Board of Health, Atlanta GA2001 WNV Season: DeKalb Co. Board of Health, Atlanta GA 2002: USGS NWHC2002: USGS NWHC (New Hire picture – not my most flattering picture) 2

ClassificationClassification Family: Flaviviridae Genus: Flavivirus Japanese Encephalitis Antigenic Complex Complex includes: Alfuy Cacipacore Japanese Encephalitis Koutango Murray Valley Encephalitis St. Louis Encephalitis Rocio Stratford Usutu West Nile Yaounde Family: Flaviviridae Genus: Flavivirus Japanese Encephalitis Antigenic Complex Complex includes: Alfuy Cacipacore Japanese Encephalitis Koutango Murray Valley Encephalitis St. Louis Encephalitis Rocio Stratford Usutu West Nile Yaounde ( /wnile.htm) 3

Transmission Cycle s/nasci/slide13.htm 4

Vector Control/Disease Prevention 5

U.S. and WNV NY99 strain closely related to Isr98NY99 strain closely related to Isr98 High avian mortality associated with human casesHigh avian mortality associated with human cases Increased sensitivity of crowsIncreased sensitivity of crows NY99 strain closely related to Isr98NY99 strain closely related to Isr98 High avian mortality associated with human casesHigh avian mortality associated with human cases Increased sensitivity of crowsIncreased sensitivity of crows 6

124,854 dead birds reported 31,514 tested (25%) 15,745 WNV-positive (50%) 8,420 crows (53%) 7,325 birds of other spp. (47%) 124,854 dead birds reported 31,514 tested (25%) 15,745 WNV-positive (50%) 8,420 crows (53%) 7,325 birds of other spp. (47%) WNV Surveillance, United States: Dead Bird Data, 2002 (as of January 2003) 7

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NWHC Submissions tested for WNV,

Frequency of Positive Submissions, NWHC # Tested % Posit ive # Tested % Posit ive # Tested % Posit ive # Tested % Posit ive American Crow Other Corvidae Birds of Prey Other Birds Mammals Herps Total

Species found with WNV infection 167 (dead) bird species167 (dead) bird species 18 mammal species18 mammal species –wolf –squirrels (grey, fox) –reindeer –sheep –harbor seal Farm-raised alligatorsFarm-raised alligators SerologySerology 167 (dead) bird species167 (dead) bird species 18 mammal species18 mammal species –wolf –squirrels (grey, fox) –reindeer –sheep –harbor seal Farm-raised alligatorsFarm-raised alligators SerologySerology 14

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Research projects 16

Ae. albopictus Ae. aegypti Ps. ferox Ae. vexans Cx. salinarius Cq. perturbans Cx. tarsalis Cx. nigripalpus Cx. pipiens Oc. canadensis Oc. atropalpus Cx. quinquefasciatusOc. cantator Oc. j. japonicus Cx. restuans Oc. sollicitans Oc. taeniorhynchus Oc. triseriatus EfficientModerateInefficient Potential vectors of West Nile virus ( based on laboratory vector competence studies) (Turrell et al., 2001, 2002) 17

Bird Reservoir Competency Study (laboratory-based) Bird Reservoir Competency Study (laboratory-based) Blue Jay (4) Common Grackle (6) Grackle (6) House Finch (2) Am. Crow (8) House Sparrow (6) Blue Jay (4) Common Grackle (6) Grackle (6) House Finch (2) Am. Crow (8) House Sparrow (6) Ring-billed gull (2) Black- billed Magpie (3) Magpie (3) Am. Robin (2) Red-winged Blackbird (3) Blackbird (3) Killdeer (2) GHO (1) Am. Kestrel (2) Fish Crow (8) Ring-billed gull (2) Black- billed Magpie (3) Magpie (3) Am. Robin (2) Red-winged Blackbird (3) Blackbird (3) Killdeer (2) GHO (1) Am. Kestrel (2) Fish Crow (8) Mallard (2) Mallard (2)European Starling (6) Starling (6) Mourning Dove (3) Northern Flicker (1) Flicker (1) Canada Goose (3) Mallard (2) Mallard (2)European Starling (6) Starling (6) Mourning Dove (3) Northern Flicker (1) Flicker (1) Canada Goose (3) Am. Coot (1) Rock Dove (6) Chicken (11) Northern Bobwhite (3) Ring-necked Pheasant (3) Budgerigar (3) Monk Parakeet (3) Parakeet (3) Japanese Quail (3) Am. Coot (1) Rock Dove (6) Chicken (11) Northern Bobwhite (3) Ring-necked Pheasant (3) Budgerigar (3) Monk Parakeet (3) Parakeet (3) Japanese Quail (3) Very Moderate Weak Not Komar et al., 2003, EID 9(3): ; 18

Experimental WNV Mortality Species n mortality rate American Crow Black-billed Magpie 5100 Blue Jay 6 83 House Finch 3 67 Fish Crow11 64 Ring-billed Gull 2 50 Common Grackle10 40 House Sparrow NO mortality in Eur. Starlings (6), Rock Doves (6), Chicken (18), Ring-necked Pheasant (3), Canada Goose (3), Am. Robin (3), Red-winged Blackbird (3), Mourning Dove (3), Budgerigar (3), Monk Parakeet (3), Japanese Quail (3), Northern Bobwhite (3) Komar et al., 2003, EID 9(3): ; 19

Alternative modes of Transmission Cage mate transmission –Am. Crow (4) –Black-billed Magpie (2) –Blue Jay (2) –Ring-billed Gull (1) –Chicken (1) Oral transmission –Am. Crow (3, susp.; 6, bird) –House Finch (1, mosq.) –House Sparrow (6, susp.) –Common Grackle (4, susp.) –GHO (1, mouse) Cloacal Shedding (crows) Cage mate transmission –Am. Crow (4) –Black-billed Magpie (2) –Blue Jay (2) –Ring-billed Gull (1) –Chicken (1) Oral transmission –Am. Crow (3, susp.; 6, bird) –House Finch (1, mosq.) –House Sparrow (6, susp.) –Common Grackle (4, susp.) –GHO (1, mouse) Cloacal Shedding (crows) Komar et al., 2003, EID 9(3): ; 20

NWHC Projects Crow StudyCrow Study OKOK Mallard StudyMallard Study Crane Vaccination StudyCrane Vaccination Study RaptorsRaptors Red-cockaded WoodpeckerRed-cockaded Woodpecker AmikihiAmikihi WaterfowlWaterfowl Crow StudyCrow Study OKOK Mallard StudyMallard Study Crane Vaccination StudyCrane Vaccination Study RaptorsRaptors Red-cockaded WoodpeckerRed-cockaded Woodpecker AmikihiAmikihi WaterfowlWaterfowl 21

Migratory Bird Sampling 22

General weakness, lethargy Emaciation Sedentary Difficulty maintaining balance, trembling Inability to walk, perch, stand, or fly Do not respond normally to danger Symptoms of WNV Infection? 23

NWHC received 56 raptorsNWHC received 56 raptors Diagnostic Testing doneDiagnostic Testing done FindingsFindings Significance?Significance? NWHC received 56 raptorsNWHC received 56 raptors Diagnostic Testing doneDiagnostic Testing done FindingsFindings Significance?Significance? NWHC Raptor Cases,

Other reports: Raptor Center at U. of MinnesotaRaptor Center at U. of Minnesota SCWDSSCWDS Other diagnostic laboratoriesOther diagnostic laboratories New York & New JerseyNew York & New Jersey Raptor rehabilitatorsRaptor rehabilitators Raptor Center at U. of MinnesotaRaptor Center at U. of Minnesota SCWDSSCWDS Other diagnostic laboratoriesOther diagnostic laboratories New York & New JerseyNew York & New Jersey Raptor rehabilitatorsRaptor rehabilitators I’ve gone blind?! Help!! 25

Other avian morbidity/mortality: Lack of birds/rapid disappearance Finches Pelicans, cranes Blue Jays…. Recrudescence of raptor cases? Lack of birds/rapid disappearance Finches Pelicans, cranes Blue Jays…. Recrudescence of raptor cases? 26

Questions still to be answered… Why the high avian mortality associated with NY99 Strain? What impact has WNV had on the bird populations? What other species are being significantly affected? What impact will WNV have on endangered/threatened bird species? Do migratory birds really play an important role in the spread of the virus? Are there other modes of transmission among bird populations? What birds are the important reservoirs for maintaining natural transmission? How is the virus over-wintering? Many, many more…. Why the high avian mortality associated with NY99 Strain? What impact has WNV had on the bird populations? What other species are being significantly affected? What impact will WNV have on endangered/threatened bird species? Do migratory birds really play an important role in the spread of the virus? Are there other modes of transmission among bird populations? What birds are the important reservoirs for maintaining natural transmission? How is the virus over-wintering? Many, many more…. ??!??!? 27