> 6,000 carcasses; >3400 to lab~ 550 WNV+> 13,000 sightings

Jul 28 Jul 8

May 19Jun 14

Sept 13

ON ALGOMA 19.1ON BRANT 19.6ON BRUCE-GREY-OWEN SOUND 17.5ON DURHAM 14ON EASTERN ONTARIO 13.1ON ELGIN-ST.THOMAS 22.2ON HALDIMAND-NORFOLK 10ON HALIBURTON-KAWARTHA 12.5ON HALTON 15.8ON HAMILTON-WENTWORTH 15.7ON HASTINGS-PRINCE EDWARD 15.4ON HURON COUNTY 16.3ON KENT-CHATHAM 13ON KINGSTON, FRONTENAC 12.8ON LAMBTON 11.9ON LEEDS, GRENVILLE, LANARK 19.6ON MIDDLESEX-LONDON 12.7ON MUSKOKA-PARRY SOUND 11.1ON NIAGARA AREA 12ON NORTH BAY 12.2ON NORTHWESTERN 17ON OTTAWA-CARLETON 15.2ON OXFORD COUNTY 14ON PEEL REGIONAL 15.6ON PERTH DISTRICT 11.5ON PETERBOROUGH 14.2ON PORCUPINE 16ON RENFREW DISTRICT 15.5ON SIMCOE COUNTY 16.1ON SUDBURY 13.4ON THUNDER BAY 21.9ON TIMISKAMING 12ON TORONTO-HEAD OFFICE 14ON WATERLOO 19.3ON WELLINGTON-DUFFERIN-GUELPH 15.7ON WINDSOR-ESSEX COUNTY 25ON YORK REGIONAL 16.8

Time elapsed - pick-up of carcass to report of test result - 2002

HumansQuebec - 1 prob; 7 confOntario -

72 prob - 5 deaths; 48 conf - 1 death

Alberta - 1 conf (US)

HorsesQuebec - 2Ontario - > 80Manitoba - ~ 150Saskatchewan - 10

Direct transmission bird-to-bird: crows, ?others- epidemiological implications- ? risk of human handling

• WNV found in many organs/tissues • high titre in oronasal cavity & feces/urine in many bird spp.

New in 2002

>100 spp of wild & pet birds susceptible

- sig. mortality in some

- Mammals: squirrels, dog, wolf, reindeer,

mountain goat etc.

Implications for wildlife populations, zoos, endangered species, handlers & rehabilitators,veterinarians, laboratorians, animal/pet owners

Implications of WNV in wild & domestic animals

New in 2002

New in 2002

Recrudescent Endemic vs. Introduced Epidemic pattern

Does WNV overwinter in mosquitoes, ?birds/mammals, to emerge again in the spring, or does it need to be reintroduced annually, presumably by migratory birds?

Implications: • predictability of recurrence; climate, overwintering vectors• overwintering - earlier initiation of cycle, longer time for amplification - ?greater human risk• bird surveillance necessary/useful or not• mosquito surveillance necessary/useful or not• larvicide or not• public health message & public attitudes

New in 2002

Recrudescent WNV?

Peel – May, 2002

Dead birds Testing, if done, may be provincial

or local responsibility

Issues: Utility of repeated testing in known WN virus-positive localities & dead bird sighting data

VecTest: 20 minute test; ~$15; 85% sensitivity, 92% specificity on oropharyngeal swab – crows; ? Useful for local testing; ?

reporting & communications; ?confirmation

WNV Surveillance 2003