West Nile Virus and Other Mosquito-borne Diseases National Surveillance Report English Edition August 21 to August 27, 2016 (Week 34)

Transcription

1 West Nile Virus and Other Mosquito-borne Diseases National Surveillance Report English Edition August 1 to August 7, (Week 3) Canada Humans: During surveillance week 3, ending on August 7,, six () human clinical cases of (WNV) have been reported to the Public Health Agency of Canada (PHAC). Of these, four cases have been reported in Manitoba and two cases in Ontario. As of surveillance week 3, a total of human clinical cases have been reported to PHAC: Manitoba (11) [Interlake-Eastern (), Prairie Mountain (), Southern (3) and Winnipeg ()], Ontario (3) [Toronto (), Niagara (1)], Quebec (1) [Capitale-Nationale], and Saskatchewan (1) [Mixed-Grass Prairie*]. Of these, five cases (31%) were classified as Neurological Syndrome, three cases (19%) as Non- Neurological Syndrome, and eight cases (5%) were unclassified. In addition, one case of asymptomatic infection has been reported in Toronto (Ontario). Mosquitoes: As of surveillance week 3, 3 (.1 %) out of 1,5 mosquito pools have tested positive for WNV in Canada: Manitoba (3), Ontario (13), Quebec (), and Saskatchewan (). Birds: As of August 7,, the Canadian Wildlife Health Cooperative, the Québec Ministry of Agriculture, Fisheries and Food, and the Québec Centre for Wildlife Health have examined a total of dead birds for WNV: Ontario (39), Quebec (3), and Saskatchewan (), of which (%) dead birds have tested positive for WNV: Ontario (5) [Toronto (1), Sarnia (1), Thorold (1), Bradford (1), Hamilton (1)]and Quebec (1). The positive birds were identified as Red- tailed Hawks (33%), American Crows (5%) and Merlins (17%). Domestic Animals: As of Aug 7,, the Canadian Food Inspection Agency has reported a total of horses that have tested positive for WNV: British Columbia (1), Manitoba (3), Saskatchewan (). United States and U.S. territories As of August 7,, the Centers for Disease Control and Prevention have reported a total of human clinical cases of disease in 3 states in the US, including the following border states: Washington (3), Idaho (), Montana (), North Dakota (11), Minnesota (), Michigan (3), and Vermont (). Of these, 19 (7%) were classified as neuroinvasive disease and (53%) were classified as non- neuroinvasive disease. Nine fatal cases have been reported. In addition, 7 presumptive viremic blood donors have been identified. Detailed information can be accessed via the CDC web site: Europe and Neighbouring Countries As of August 7,, 5 human cases of WNV have been reported in the European Union and 3 cases have been reported in the neighbouring countries. Detailed information can be accessed via the ECDC web site: *Mixed-Grass Prairie (Sun Country, Regina Qu Appelle, Five Hills, Cypress, Heartland Health Regions) FIGURE 1: Geographic distribution of Human Clinical cases of WNV in Canada, as of August 7,

2 FIGURE : WNV Human Clinical cases and Asymptomatic Infections, by Province/ Territory and by Report week, as of August 7, Counts 1 1 New Brunswick Nunavut Northwest Territory Yukon Territory British Columbia Alberta Saskatchewan Manitoba Ontario Quebec Nova Scotia Prince Edward Island Newfoundland and Labrador Report Week * FIGURE 3: WNV Human Clinical cases and Asymptomatic Infections by Report week for selected years, in Canada Counts Report Week by Episode Date * clinical cases and asymptomatic infections are grouped by report week, based on episode date. Episode date could include one of the following: onset date, diagnosis date, lab sample date or reporting date.

3 TABLE 1: West Nile Virus Human Clinical cases and Asymptomatic Infections by Province/Territory for the current report week and year to date, season Newfoundland and Labrador neurological non-neurological Week 3: August 1 to August 7, Unclassified/ unspecified Total clinical cases 1 Number of travel-related cases asymptomatic infection 3 Prince Edward Island Nova Scotia New Brunswick Quebec Ontario Manitoba 1 3 Saskatchewan Alberta British Columbia Yukon Territory Northwest Territory Nunavut Total 1 Newfoundland and Labrador neurological non-neurological Year to date: January 1 to August 7, Unclassified/ unspecified Total clinical cases 1 Number of travel-related cases asymptomatic infection 3 Prince Edward Island Nova Scotia New Brunswick Quebec 1 1 Ontario Manitoba 3 11 Saskatchewan 1 1 Alberta British Columbia Yukon Territory Northwest Territory Nunavut Total Total clinical cases is the sum of both probable and confirmed: neurological and non-neurological s, along with any unclassified or unspecified cases. Likely related to travel outside the Province/Territory. These cases are included in either the total clinical cases or asymptomatic infections. 3 Satisfies diagnostic test criteria in the absence of clinical criteria. This category could include asymptomatic blood donors whose blood is screened using a nucleic acid amplification test, by blood operators (i.e. Canadian Blood Services or Hema-Quebec) and is subsequently brought to the attention of public health officials. Blood operators in Canada perform a supplementary specific nucleic acid amplification test following any positive donor screen test result.

4 TABLE : Number of mosquito pools tested and number of positive mosquito pools by Province/Territory, season Province Year to date: January 1 to August 7, Number of positive mosquito Number of mosquito pools pools tested Percentage of positive mosquito pools (%) Quebec Ontario Manitoba Saskatchewan Total In, mosquito surveillance is conducted by the following provinces only: Quebec, Ontario, Manitoba and Saskatchewan TABLE 3: Number of WNV positive mosquito pools/ Total number of WNV mosquito pools tested by Report week and by Province/ Territory, season ǂ ince / Report week of tory foundland abrador e Edward d swick Scotia ec /59 /7 /5 /7 /9 /79 / / rio / /5 /1 /9 /9 /19 / /5 /5 / 1/795 / 5/9 /97 3/97 3/ / itoba / / /3 /17 /5 /5 /9 /1 /113 7/19 5/1 / 15/3 1/3 tchewan /1 /9 / / 1/ /37 /31 3/ 1/7 / 1/117 / rta h mbia n tory hwest tory avut l / /5 /1 /53 /9 /19 / / /3 3/95 1/999 /97 17/93 39/135 5/137 1/1 9/151 ǂ Detailed mosquito surveillance data can be accessed through Provincial/ Territorial websites. _These jurisdictions do not maintain regular mosquito surveillance.

5 FIGURE : Reported number of dead birds tested positive for WNV by Province/ Territory and by Report week, season in Canada Number of dead birds testing positive 1 1 Nunavut Northwest Territory Yukon Territory British Columbia Alberta Saskatchewan Manitoba Ontario Quebec Nova Scotia New Brunswick Prince Edward Island Newfoundland and Labrador Report Week FIGURE 5: Percentage of dead birds tested positive for WNV by Report week in 1, 15 and, and number of dead birds tested positive for WNV, by Report week,, in Canada % Positive Report Week % positive 1 % positive 15 % positive # positve # Positive Not all provinces are conducting dead bird surveillance as part of their own WNV surveillance program. However, WNV positive dead birds may be identified through the National Wildlife Disease Surveillance Program of the Canadian Wildlife Health Cooperative (CWHC)