West Nile Virus and Other Mosquito-Borne Disease National Surveillance Report - September 14 to September 20, 2014 (Report Week 38)

Summary

Canada

Humans: During surveillance week 38 (September 14 to September 20, 2014), one human clinical case of West Nile virus neurological syndrome was reported in Quebec: Montérégie.

As of surveillance week 38, 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)* 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 these, seven (38.9%) are clinically 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 CountyNote de bas de page 1

Mosquitoes: As of surveillance week 38, a reported 212 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)]; 112 in Quebec [Laval (10), Montérégie (41) and Montreal (61)] and 20 in Saskatchewan.

Dead Birds: During surveillance week 38, the Canadian Wildlife Health Cooperative tested two dead birds for West Nile virus in Canada: Ontario (1) and Quebec (1). These birds have tested positive for West Nile virus.

As of surveillance week 38, the Canadian Wildlife Health Cooperative tested 105 dead birds for West Nile virus in Canada: Ontario (24), Quebec (17) and Saskatchewan (64). Of these, 14 (13.3%) were positive for West Nile virus in Canada: Ontario (6), Quebec (6) and Saskatchewan (2).

Domestic Animals: As of surveillance week 38, the Canadian Food Inspection Agency reported 13 horses have tested positive for West Nile virus in Canada: Alberta (6), Quebec (1) and Saskatchewan (6).

United States

As of September 16, 2014, the Centers for Disease Control and Prevention (CDC) has reported 725 West Nile virus human disease cases:

Arizona (30), Arkansas (2), California (237), Colorado (41), Connecticut (1), District of Columbia (2), Florida (5), Georgia (6), Idaho (13), Illinois (8), Indiana (3), Iowa (11), Kansas (10), Louisiana (78), Maryland (2), Massachusetts (1), Michigan (1), Minnesota (6), Mississippi (25), Missouri (4), Montana (4), Nebraska (36), Nevada (2), New Jersey (3), New Mexico (5), New York (9), North Dakota (9), Ohio (4), Oklahoma (10), Pennsylvania (3), South Carolina (2), South Dakota (35), Tennessee (5), Texas (91), Utah (1), Virginia (3), Washington (7), Wisconsin (5) and Wyoming (5).

Of these, 398 (54.9%) were diagnosed as neuroinvasive disease cases and 327 (45.1%) as non-neuroinvasive disease cases. Twenty-five fatal cases were reported. One hundred and seventy-one presumptive viremic blood donors have been identified.

European Union, European Economic Area and Neighbouring Countries

During surveillance week 38, the European Centre for Disease Prevention and Control (ECDC) reported five new human cases of West Nile fever in Europe: Greece (2), Italy (1) and Romania (2). In the neighboring countries, 17 new human cases were reported: Russian Federation (4) and Serbia (13).

As of September 11, 2014, 42 human cases of West Nile fever have been reported in Europe: Austria (1), Greece (15), Hungary (2), Italy (9) and Romania (15). In the neighbouring countries, 94 human cases were reported: Bosnia and Herzegovina (13), Israel (2), Russian Federation (28) and Serbia (51).

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                  
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                  
New Brunswick 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                  
Quebec 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 0 1                  
Ontario 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 2 0 2 5 1 0                  
Manitoba 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1Note de bas de page ** 2 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                  
Alberta 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                  
Yukon Territory 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                  
Nunavut 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 4Note de bas de page * 3 3 6 1 1                  
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 38: September 14 to September 20, 2014
West Nile virus Neurological syndrome West Nile virus Non-Neurological syndrome Unclassified/
Unspecified
Total clinical
casesNote de bas de page 1
Number of travel
related casesNote de bas de page 2
West Nile virus
asymptomatic infectionsNote de bas de page 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 1 0 0 1 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 1 0 0 1 0 0
  Year to date: January 1 to September 20, 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 1Note de bas de page ** 1 3Note de bas de page * 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 7Note de bas de page * 4 18Note de bas de page * 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 4Note de bas de page * 3 3 6 1 1
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 season Note de bas de page *
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
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
New Brunswick 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
Quebec 0 0 0 0 0 0 0 0 0 0 0 0 1 4 9 10 19 19Note de bas de page ** 39 70 99 112
Ontario 0 0 0 0 0 0 0 0 0 0 0 0 0 2 5 9 11 13 30 43 52 56
Manitoba 0 0 0 0 0 0 0 0 0 0 0 0 0 0 7 7 14 19 22 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
Alberta 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
Yukon Territory 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
Nunavut 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
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 September 20, 2014
Number of mosquito
pools tested
Number of positive
mosquito pools
Percentage of positive
mosquito pools (%)
Quebec 10,057 112 1.1
Ontario 13,272 56 0.4
Manitoba 1,505 24 1.6
Saskatchewan 824 20 2.4
British Columbia 236 0 0
Total 25,894 212 0.8

Figure 3. 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 season Note de bas de page *
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
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
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
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
Quebec 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 1 0 2 1 6
Ontario 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 3 0 0 1 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
Saskatchewan 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 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
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
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
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
Nunavut 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 2 14

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

Notes de bas de page

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