The Incursion and Expansion of West Nile Virus into Canada

Transcription

1 The Incursion and Expansion of West Nile Virus into Canada Paul Sockett PhD I.K. Barker, M. Drebot, R.Lindsay, H. Artsob, and P. Buck Hosted by Paul Webber Acknowledgement We wish to acknowledge the contribution of our federal and provincial partners who participate in the National West Nile Virus Surveillance Program Partners in West Nile virus Surveillance and Response Public Health Agency of Canada Pest Management Regulatory Agency First Nations and Inuit Health Branch Healthy Environments and Consumer Safety Branch Health Products and Food Branch Communications, Marketing and Consultation Directorate Provincial/Territorial Steering Committees Canadian Food Inspection Agency Department of National Defence Department of Fisheries and Oceans International Linkages Blood Operators Consumers Groups Canadian Cooperative Wildlife Health Centre Chief Medical Officers of Health Environment Canada Parks Canada Health Professional Organizations Surveillance in Canada: 2-24 Monitoring activities include surveillance in: Dead birds Mosquitoes Horses Humans 2 Results: Canada 2 First confirmed positive dead bird collected in Windsor, Ontario on 8 ust WN virus was confirmed in 28 dead birds from 2 health regions in Ontario Virus also confirmed in nine mosquito pools from Ontario WN virus confirmed in pool of over-wintering mosquitoes, collected January 22

2 Positive Test Results: Canada 2 Province Number of Confirmed Positive Dead Birds Number of Confirmed Positive Mosquito Pools Number of Presumptive* or Confirmed Positive Horses Ontario 28 9 Canada 28 9 * Requires additional testing before it can be considered a confirmed result 22 Results Canada 22 () First confirmed positive dead bird found on 9 May in Peel Region, southern Ontario Quebec confirmed first two positive dead birds found on 3 June in Montreal-Centre Ontario confirmed first positive mosquito pool collected on 27 June in York Region Manitoba confirmed first positive dead bird found on 2 y in Interlake Region Results Canada 22 (2) Saskatchewan confirmed first positive dead bird found on 28 y in the city of Regina Quebec confirmed first positive mosquito pool collected on ust in Oka Manitoba confirmed first two positive mosquito pools collected on 8 ust in Winnipeg Manitoba announced first presumptive positive horses on 6 ust Nova Scotia confirmed first positive dead bird found on 2 ust in Halifax Region Canada to the last week of December Provinces with WN virus activity NS, QC, ON, MB, SK Human cases (2) Dead birds Domestic Animals Mosquito Pools 3 35 WNv activity in a bird, mosquito pool, horse or human 2 probable and confirmed (number of deaths in brackets) 3 confirmed positive (number tested in brackets) 4 presumed or confirmed 5 Several cases are related to travel outside Canada 6 These figures represent the number of positive results reported to the CFIA as per the Immediately Notifiable Disease Regulations

3 Spatial distribution in Ontario, 22 Toronto (6.23) Peel (5.36) Halton (4.9) Hamilton-Wentworth (3.5) Niagara (4.2) Windsor-Essex (9.34) Alternate Modes of Transmission of Human Infection due to WN virus: Canada 22 Route of transmission Presumed Confirmed Blood transmission Tissue/organ transplant Breast milk Transplacental Needle/Scalpel blade 23

4 Key Findings for 23 - Canada () Key Findings for 23 Canada (2) Human cases from 24 y to late November; peak from late ust to late tember 494 human cases (46 WNNS), 4 deaths First confirmed positive bird in Ontario in mid-april by June, positives birds from Alberta to East Coast 633/,332 positive birds in 23 (556/3,29 in 22 Culex spp. primary vector (Culex tarsalis in West and Culex pipiens/culex restuans in East) 445 positive horses, most in AB (8) and SK (62) 9 8 Number of human cases of West Nile Virus by classification and symptom onset date in Canada 23 (n=427, excludes 3 cases missing onset dates, 3 cases unclassified) West Nile Fever (n=23, 27 missing onset) West Nile Neurological Syndrome (n=24, 3 missing onset) Age profile of human cases of West Nile virus by classification in Canada Classified Cases Mean (SE) Median Range n No. cases WNv Fever 46. (.5) 3 to WNv Neurological Syndromes 55. (.2) 54 to Jun 2 Jun All cases.4 (.4) to Number and rate of West Nile virus illness by age group in Canada 23 (n=) Rate of West Nile virus illness by classification and age group in Canada 23 (n=457, excludes 3 unknown classification) Number of Cases Number of cases Rate per, to 9 to 9 2 to 29 3 to 39 4 to 49 5 to 59 6 to 69 7 to 79 8 to 89 9 and over Age group (years) Rate per, Rate per, West Nile Fever West Nile Neurological Syndrome to 9 to 9 2 to 29 3 to 39 4 to 49 5 to 59 6 to 69 7 to 79 8 to 89 9 and over.3.3

5 24 9 Number of, and Percentage of, Dead Birds Tested Positive for WNV, by Report Week, Canada 23 & % +ve % +ve % Positive # +ve 24 # +ve 5 # positive Report Week Number of human cases of West Nile Virus by classification and symptom onset date in Canada 24 (n=25) 5 Cumulative WNV Human Cases, by Report Week, Canada, 23 & 24 5 West Nile Fever (n=2) West Nile Neurological Syndrome (n=3) 4 Cumulative # cases 5 No. cases Report Week Jun 2 Jun by week of disease symptom onset 24 by best available episode date

6 Age profile of human cases of West Nile virus by classification in Canada 23 Classified Cases Mean (SE) Median Range n WNv Fever WNv Neurological Syndromes All cases 24 Classified Cases WNv Fever WNv Neurological Syndromes All cases 46. (.5) 55. (.2).4 (.4) Mean (SE) 44.6 (5.2) 48.5 (6.3) 46.6 (4.) 54 Median to 92 to 92 to 92 Range 5 to 83 3 to 88 3 to n Number of Cases Number of cases Rate per,.3 Number and rate of West Nile virus illness by age group in Canada 24 (n=25) to 9 to 9 2 to 29 3 to 39 4 to 49 5 to 59 6 to 69 7 to 79 8 and over Age group (years) Rate per,.4.2. Rate of West Nile virus illness by classification and age group in Canada 24 (n=25) West Nile Fever West Nile Neurological Syndrome..2. Communications Approach To date Served as a credible source of information Ensured consistent messaging and reached high risk populations Rate per, to 9 to 9 2 to 29 3 to 39 4 to 49 5 to 59 6 to 69 7 to 79 8 to 89 For 25, PHAC will continue its coordinating role with regional offices, P/Ts and other federal Departments. Key objective will be to sustain messaging while supporting provincial/territorial efforts Facilitate information-sharing through communications committee Continue public education with in-store promotion FNIHB s public education campaign will focus on personal protective measures (avoiding mosquito bites and eliminating sources of standing water) Host media technical briefing early in the season Canada to the last week of December Summary Provinces with WN virus activity NS, QC, ON, MB, SK NS, NB, QC, ON, MB, SK, AB QC, ON, MB, SK, AB Human cases (2) (4) 26 5 (2) Dead birds (332) 46 (6236) Domestic Animals Mosquito Pools WNv activity in a bird, mosquito pool, horse or human 2 probable and confirmed (number of deaths in brackets) 3 confirmed positive (number tested in brackets) 4 presumed or confirmed 5 Several cases are related to travel outside Canada 6 These figures represent the number of positive results reported to the CFIA as per the Immediately Notifiable Disease Regulations

7 West Nile virus Spread: ust 999 to December 24 Human Cases Canada and USA: Year Canada USA (6) 2(2) USA 62 (6) 2 (2) 66 (9) 456 (284) 9862 (264) 2 (88) 23 Dominican Republic. Cayman (2) 388 (4) 66(9) 456 (284) 9862 (264) Canada 426 (2) 494 (4) 26 (2) Islands () 2 (88) (number of deaths in brackets) (number of deaths in brackets)

8 For more information, please consult the Public Health Agency of Canada s WN virus website at: Pour plus d informations, consulter le site Web d Agence de santé publique du Canada sur le virus du Nil occidental à l adresse suivante: Other 25 Teleclasses For more information, refer to /schedule.cfm June 2 Skin Rashes & Infection Control Spot That Spot with Dr. Justin Graham June 9 Measuring the Cost of Hospital Infection with Dr. Barry Cookson June 4 Controlling Mumps in the Community with Dr. Isabel Oliver June 6 Antiseptic Practice and Procedure with Sue Crow June 3 Infection Control in First Response Emergency Services with Margaret McKenzie Questions? Contact Paul Webber paul@webbertraining.com