West Nile Virus and Other Mosquito-Borne Disease National Surveillance Report - September 28 to October 4, 2014 (Report Week 40)

Summary

Canada

Humans: During surveillance week 40 (September 28 to October 4, 2014), no human cases of West Nile virus were reported to the Public Health Agency of Canada.

As of surveillance week 40, 18 human clinical cases of West Nile virus have been reported in Canada: three in Manitoba [Interlake-Eastern Health Region (1), Prairie Mountain Health Region (1)Footnote 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 five in Quebec [Lanaudière (1), Montérégie (2) and Montreal (2)].

Of the 18 human clinical cases, seven (38.9%) are classified as West Nile virus neurological syndrome, seven (38.9%) as West Nile virus non-neurological syndrome and four (22.2%) as unclassified/unspecified.

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

Mosquitoes: As of surveillance week 40, 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: During surveillance week 40, the Canadian Wildlife Health Cooperative tested two dead birds for West Nile virus in Canada: Quebec (1) and Saskatchewan (1) and none were reported positive for West Nile virus.

As of surveillance week 40, the Canadian Wildlife Health Cooperative tested 114 dead birds for West Nile virus in Canada: Ontario (24), Quebec (21) and Saskatchewan (69). Of these, 15 (13.2%) dead birds have tested positive for West Nile virus in Canada: Ontario (6), Quebec (7) and Saskatchewan (2).

Domestic Animals: As of surveillance week 40, the Canadian Food Inspection Agency reported 16 horses have tested positive for West Nile virus in Canada: Alberta (7), Ontario (1), Quebec (2) and Saskatchewan (6).

United States

As of September 30, 2014, the Centers for Disease Control and Prevention (CDC) reported 1,177 West Nile virus human disease cases:

Alabama (1), Arizona (42), Arkansas (5), California (374), Colorado (90), Connecticut (3), District of Columbia (3), Florida (7), Georgia (10), Idaho (18), Illinois (19), Indiana (3), Iowa (11), Kansas (23), Louisiana (102), Maryland (2), Massachusetts (3), Michigan (1), Minnesota (9), Mississippi (40), Missouri (9), Montana (4), Nebraska (82), Nevada (3), New Jersey (5), New Mexico (14), New York (15), North Dakota (17), Ohio (6), Oklahoma (13), Pennsylvania (6), South Carolina (2), South Dakota (49), Tennessee (6), Texas (155), Utah (1), Virginia (3), Washington (8), Wisconsin (8) and Wyoming (5).

Of these, 656 (55.7%) were diagnosed as neuroinvasive disease cases and 521 (44.3%) as non-neuroinvasive disease cases. Forty-three fatal cases were reported. Two hundred and twenty presumptive viremic blood donors have been identified.

European Union, European Economic Area and Neighbouring Countries

During surveillance week 40, the European Centre for Disease Prevention and Control (ECDC) reported 13 human cases of West Nile fever in Europe: Hungary (3), Italy (5) and Romania (5). In the neighbouring countries, seven human cases were reported in Israel.

As of October 2, 2014, 68 human cases of West Nile fever have been reported in Europe: Austria (1), Greece (15), Hungary (11), Italy (19) and Romania (22). In the neighbouring countries, 109 human cases were reported: Bosnia and Herzegovina (13), Israel (9), Russian Federation (29) and Serbia (58).

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

* West Nile virus 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.

Table 1: West Nile Virus clinical cases and asymptomatic infections, by Province/Territory and by 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 45 46 47
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
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
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
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
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
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
Manitoba 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1Footnote ** 2 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
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
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
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
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
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
Total 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 4Footnote * 3 3 6 1 1 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 Week 40: September 28 to October 4, 2014
West Nile virus neurological syndrome West Nile virus non-neurological syndrome Unclassified/
unspecified
Total clinical
casesFootnote 1
Number of travel
related casesFootnote 2
West Nile virus
asymptomatic infectionsFootnote 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 October 4, 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 4 1 0 5 0 0
Ontario 2 5 3 10 2 1
Manitoba 1 1Footnote ** 1 3Footnote * 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 7 7Footnote * 4 18Footnote ** 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 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.

Table 3: West Nile Virus clinical cases and asymptomatic infections by report week for selected years
Years 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 45 46 47
2014 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 4Footnote * 3 3 6 1 1 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 seasonFootnote *
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 45 46 47
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
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
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
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
Quebec 0 0 0 0 0 0 0 0 0 0 0 0 1 4 9 10 19 19Footnote ** 39 70 99 112 119 119
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
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
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
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
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
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
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
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
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
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 October 4, 2014
Number of positive mosquito
pools
Number of
mosquito pools tested
Percentage of positive
mosquito pools (%)
Quebec 119 10,555 1.1
Ontario 56 14,020 0.4
Manitoba 24 1,505 1.6
Saskatchewan 20 824 2.4
British Columbia 0 236 0
Total 219 27,140 0.8

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

* Data from the Canadian Wildlife Health Cooperative

Table 5: Reported number of dead birds testing positive for West Nile Virus by Province/Territory and by report week, 2014 seasonFootnote *
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 45 46 47 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
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
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
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
Quebec 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 1 0 2 2 0 0 7
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 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
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 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
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
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
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
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
Total 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 2 2 4 0 2 3 0 0 15

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

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 0
Numbers tested 2014 0 0 0 0 0 0 0 0 0 0 0 0 0 41Footnote * 10 13 9 7 13 6 10 3 0 2
Percentage positive 2014 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 15 22 29 31 0 20 100 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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