West Nile Virus and Other Mosquito-Borne Disease National Surveillance Report - October 19 to October 25, 2014 and October 26 to November 1, 2014 (Report Weeks 43 and 44)

Summary

West Nile Virus in Canada

Humans: During surveillance week 43 (October 19 to October 25, 2014) and 44 (October 26 to November 1, 2014), no human cases of West Nile virus were reported to the Public Health Agency of Canada.

As of surveillance week 43 and 44, 21 human clinical cases of West Nile virus have been reported in Canada: five in Manitoba [Interlake-Eastern Health Region (1), Prairie Mountain Health Region (2)Footnote *, Southern Health Region (1) and Winnipeg Health Region (1)], 10 in Ontario [Chatham-Kent (1), Halton Region (2), Lambton County (1), City of Ottawa (2), Simcoe-Muskoka District (1) and City of Toronto (3)] and six in Quebec [Lanaudière (1), Montérégie (3) and Montreal (2)].

Of the 21 human clinical cases, 10 (47.6%) are classified as West Nile virus non-neurological syndrome, nine (42.9%) as West Nile virus neurological syndrome and two (9.5%) as unclassified/unspecified.

One asymptomatic infection has been reported in Ontario: Windsor-Essex County.

Mosquitoes: As of surveillance week 43 and 44, a reported 219 mosquito pools have tested positive for West Nile virus in Canada: 24 in Manitoba [Interlake-Eastern Health Region (7), Prairie Mountain Health Region (1), Southern Health Region (11) and Winnipeg Health Region (5)]; 56 in Ontario [Haliburton-Kawartha-Pine Ridge District (1), Halton Regional (3), City of Hamilton (7), Lambton (1), Middlesex-London (4), Niagara Regional (2), City of Ottawa (3), Peel Regional (22), City of Toronto (10), Windsor-Essex County (1) and York Regional (2)]; 119 in Quebec [Laval (13), Montérégie (42) and Montreal (64)] and 20 in Saskatchewan.

Dead Birds: As of surveillance week 43 and 44, the Canadian Wildlife Health Cooperative tested 121 dead birds for West Nile virus in Canada: Ontario (30), Quebec (21) and Saskatchewan (70). Of these, 16 (13.2%) dead birds have tested positive for West Nile virus in Canada: Ontario (6), Quebec (8) and Saskatchewan (2).

Domestic Animals: As of surveillance week 43 and 44, the Canadian Food Inspection Agency reported 21 horses have tested positive for West Nile virus in Canada: Alberta (7), Manitoba (1), Ontario (1), Quebec (4) and Saskatchewan (8).

West Nile Virus Human Disease Cases in the United States

As of October 28, 2014, the Centers for Disease Control and Prevention (CDC) reported 1,668 West Nile virus human disease cases:

Alabama (2), Arizona (67), Arkansas (6), California (608), Colorado (108), Connecticut (5), District of Columbia (3), Florida (13), Georgia (11), Idaho (18), Illinois (36), Indiana (8), Iowa (12), Kansas (41), Louisiana (111), Maryland (6), Massachusetts (5), Michigan (1), Minnesota (14), Mississippi (45), Missouri (12), Montana (5), Nebraska (120), Nevada (3), New Jersey (7), New Mexico (20), New York (18), North Dakota (22), Ohio (9), Oklahoma (16), Pennsylvania (10), South Carolina (2), South Dakota (57), Tennessee (6), Texas (207), Utah (2), Virginia (6), Washington (12), Wisconsin (8) and Wyoming (5).

Of these, 976 (58.5%) were diagnosed as neuroinvasive disease cases and 692 (41.5%) as non-neuroinvasive disease cases. Fifty-eight fatal cases were reported. Two hundred and seventy-five presumptive viremic blood donors have been identified.

West Nile Fever in the European Union, European Economic Area and Neighbouring Countries

During surveillance week 43, the European Centre for Disease Prevention and Control (ECDC) reported one human case of West Nile fever in Romania. In the neighbouring countries, no cases were reported.

As of October 23, 2014, 74 human cases of West Nile fever have been reported in Europe: Austria (1), Greece (15), Hungary (11), Italy (24) and Romania (23). In the neighbouring countries, 120 human cases were reported: Bosnia and Herzegovina (13), Israel (9), Russian Federation (29) and Serbia (69).

Figure 1. West Nile Virus clinical cases and asymptomatic infections, by Province/Territory and report week, 2014 season

West Nile Virus clinical cases and asymptomatic infections, by Province/Territory and report week, 2014 season.
Table 1: West Nile Virus clinical cases and asymptomatic infections, by Province/Territory and report week, 2014 season
Provinces and Territories Report week of 2014
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44
Newfoundland and Labrador 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Prince Edward Island 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Nova Scotia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
New Brunswick 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Quebec 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 0 1 0 0 1 0 0 0
Ontario 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 2 0 2 5 1 0 0 0 0 0 0 0
Manitoba 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1Table 1 - Footnote ** 2 2 0 0 0 0 0 0 0 0 0
Saskatchewan 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Alberta 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
British Columbia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Yukon Territory 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Northwest Territory 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Nunavut 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Total 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 4Table 1 - Footnote * 3 5 6 1 1 0 0 1 0 0 0
Table 2: West Nile Virus human clinical cases and asymptomatic infections by Province/Territory for the current report week and year to date, 2014 season
Provinces and Territories Weeks 43 and 44: October 19 to October 25, 2014 and October 26 to November 1, 2014
West Nile virus neurological syndrome West Nile virus non-neurological syndrome Unclassified/ unspecified Total clinical
casesTable 2 - Footnote 1
Number of travel-related casesTable 2 - Footnote 2 West Nile virus asymptomatic infectionsTable 2 - Footnote 3
Newfoundland and Labrador 0 0 0 0 0 0
Prince Edward Island 0 0 0 0 0 0
Nova Scotia 0 0 0 0 0 0
New Brunswick 0 0 0 0 0 0
Quebec 0 0 0 0 0 0
Ontario 0 0 0 0 0 0
Manitoba 0 0 0 0 0 0
Saskatchewan 0 0 0 0 0 0
Alberta 0 0 0 0 0 0
British Columbia 0 0 0 0 0 0
Yukon Territory 0 0 0 0 0 0
Northwest Territory 0 0 0 0 0 0
Nunavut 0 0 0 0 0 0
Total 0 0 0 0 0 0
  Year to date: January 1 to November 1, 2014
Newfoundland and Labrador 0 0 0 0 0 0
Prince Edward Island 0 0 0 0 0 0
Nova Scotia 0 0 0 0 0 0
New Brunswick 0 0 0 0 0 0
Quebec 5 1 0 6 0 0
Ontario 3 5 2 10 2 1
Manitoba 1 4Table 2 - Footnote * 0 5Table 2 - Footnote * 0 0
Saskatchewan 0 0 0 0 0 0
Alberta 0 0 0 0 0 0
British Columbia 0 0 0 0 0 0
Yukon Territory 0 0 0 0 0 0
Northwest Territory 0 0 0 0 0 0
Nunavut 0 0 0 0 0 0
Total 9 10Table 2 - Footnote * 2 21Table 2 - Footnote * 2 1

Figure 2. West Nile Virus clinical cases and asymptomatic infections by report week for selected years

West Nile Virus clinical cases and asymptomatic infections by report week for selected years
Table 3: West Nile Virus clinical cases and asymptomatic infections by report week for selected years
Year Report week
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
2014 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 4Table 3 - Footnote * 3 5 6 1 1 0 0 1 0 0 0 - - -
2013 1 0 0 0 0 1 1 0 0 0 1 2 1 5 5 8 17 11 13 13 11 9 1 6 1 0 4 1 0 1 0
2012 1 0 0 0 0 0 0 0 0 0 3 5 11 16 27 53 63 57 43 43 45 24 30 14 9 5 1 0 0 0 0
2007 0 0 0 0 0 0 2 2 3 4 11 35 36 72 139 424 471 443 287 182 116 71 30 18 10 11 5 4 2 0 0
2005 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 4 11 28 28 38 45 27 15 7 12 3 3 1 0 0 0
2003 0 0 0 0 0 0 0 0 0 1 1 1 5 11 9 27 66 249 323 324 178 107 82 37 14 8 4 3 0 0 0
Table 4.1: Reported cumulative number of West Nile Virus positive mosquito pools by Province/Territory and by report week, 2014 seasonTable 4.1 - Footnote *
Provinces and Territories Report week of 2014
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44
Newfoundland and Labrador 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Prince Edward Island 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
New Brunswick 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Nova Scotia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Quebec 0 0 0 0 0 0 0 0 0 0 0 0 1 4 9 10 19 19Table 4.1 - Footnote ** 39 70 99 112 119 119 119 119 119 119
Ontario 0 0 0 0 0 0 0 0 0 0 0 0 0 2 5 9 11 13 30 43 52 56 56 56 56 56 56 56
Manitoba 0 0 0 0 0 0 0 0 0 0 0 0 0 0 7 7 14 19 22 24 24 24 24 24 24 24 24 24
Saskatchewan 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 2 9 19 20 20 20 20 20 20 20 20 20 20
Alberta 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
British Columbia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Yukon Territory 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Northwest Territory 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Nunavut 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Total 0 0 0 0 0 0 0 0 0 0 0 0 1 7 22 28 53 70 111 157 195 212 219 219 219 219 219 219
Table 4.2: Number of mosquito pools tested and number of positive mosquito pools by Province/Territory, 2014 season
Provinces and Territories Year to date: January 1 to November 1, 2014
Number of positive mosquito pools Number of mosquito pools tested Percentage of positive mosquito pools (%)
Quebec 119 11,413 1.0
Ontario 56 14,116 0.4
Manitoba 24 1,505 1.6
Saskatchewan 20 824 2.4
British Columbia 0 236 0
Total 219 28,094 0.8

Figure 3. Reported number of dead birds testing positive for West Nile Virus by Province/Territory and by report week, 2014 seasonFigure 3 - Footnote *

Reported number of dead birds testing positive for West Nile Virus by Province/Territory and by report week, 2014 season
Table 5: Reported number of dead birds testing positive for West Nile Virus by Province/Territory and by report week, 2014 seasonTable 5 - Footnote *
Provinces and Territories Report week of 2014
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 Total
Newfoundland and Labrador 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Prince Edward Island 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
New Brunswick 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Nova Scotia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Quebec 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 1 0 2 2 0 1 0 0 0 0 8
Ontario 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 3 0 0 1 0 0 0 0 0 0 6
Manitoba 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Saskatchewan 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 2
Alberta 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
British Columbia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Yukon Territory 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Northwest Territory 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Nunavut 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Total 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 2 2 4 0 2 3 0 1 0 0 0 0 16

Figure 4. Percentage of dead birds testing positive for West Nile Virus in the 2014 season by report week, as compared to the 2003, 2012 and 2013 seasons

Percentage of dead birds testing positive for West Nile Virus in the 2014 season by report week, as compared to the 2003, 2012 and 2013 seasons
Table 6: Percentage of dead birds testing positive for West Nile Virus in the 2014 season by report week, as compared to the 2003, 2012 and 2013 seasons
  Report week of 2014
17 18 19 20 21 22 23 24 26 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
Numbers positive 2014 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 2 2 4 0 2 3 0 1 0 0 0 0 - - -
Numbers tested 2014 0 0 0 0 0 0 0 0 0 0 0 0 0 41Table 6 - Footnote * 10 13 9 7 13 6 10 4 1 4 2 1 0 0 - - -
Percentage positive 2014 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 15 22 29 31 0 20 75 0 25 0 0 0 0 - - -
Numbers positive 2013 0 0 0 0 0 0 0 0 0 1 0 0 5 2 13 9 6 6 18 9 6 6 2 0 1 0 0 0 0 0 0
Numbers tested 2013 0 0 0 1 0 0 0 2 2 5 8 5 9 10 29 19 16 16 24 13 9 10 3 3 2 0 0 0 0 0 0
Percentage positive 2013 0 0 0 0 0 0 0 0 0 20 0 0 56 20 45 47 38 38 75 69 67 60 67 0 50 0 0 0 0 0 0
Percentage positive 2012 0 0 0 0 0 0 0 0 0 0 33 67 33 67 33 50 67 64 67 33 67 67 55 0 0 0 0 0 0 0 0
Percentage positive 2003 0 0 1 0 1 1 1 1 1 3 3 6 7 10 17 21 38 35 43 46 45 45 58 29 20 15 8 0 0 0 0
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