West Nile Virus and Other Mosquito-Borne Disease National Surveillance Report - July 12 to July 18, 2015 (Report Week 28)

Summary

West Nile Virus in Canada

Humans: During surveillance week 28 (July 12 to July 18, 2015), Ontario reported one human case of West Nile virus in Waterloo Region. The case is unclassified. Up to week 28, there has been one human case reported to the Public Health Agency of Canada.

Mosquitoes: As of surveillance week 28, there are four mosquito pools tested positive for West Nile virus in Canada: Ontario (2), Manitoba (1) and Saskatchewan (1). 

Dead Birds: As of surveillance week 28, the Canadian Wildlife Health Cooperative tested 1 dead bird positive for West Nile virus in Canada: Ontario (1).

Domestic Animals As of surveillance week 28, the Canadian Food Inspection Agency reported no horses that have tested positive for West Nile virus in Canada.

West Nile Virus Human Disease Cases in the United States

As of July 14, 2015, the Centers for Disease Control and Prevention (CDC) reported 17 human cases of West Nile virus:

Arizona (1), Colorado (1), Delaware (1), Kansas (2), Montana (1), Nebraska (1), New Mexico (1), Oklahoma (3), South Dakota (1), Texas (3), Washington (1) and Wyoming (1).

Of these, 6 (35,3%) were diagnosed as neuroinvasive disease cases, 11 (64,7%) as non-neuroinvasive disease cases. No fatal cases were reported. Seven presumptive viremic blood donors have been identified.

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

During surveillance week 28, the European Centre for Disease Prevention and Control (ECDC)  no human cases of West Nile fever were reported.

Since surveillance week 26 one human case of West Nile fever in Bulgaria was reported. In the neighbouring countries, no cases were reported.

FIGURE 1: West Nile Virus clinical cases and asymptomatic infections, by Province/Territory and by report week, 2015 season

text description in table 1 below
TABLE 1: West Nile Virus clinical cases and asymptomatic infections, by Province/Territory and by report week, 2015 season
  Report week of 2015
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

Table 1 Footnotes

Table 1 Footnote 1

Unclassified/unspecified case.

Return to table 1 footnote 1 referrer

Newfoundland and Labrador 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                                      
New Brunswick 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                                      
Quebec 0 0 0 0 0 0 0 0 0 0 0 0                                      
Ontario 0 0 0 0 0 0 0 0 0 0 0 1Table 1 Footnote 1                                      
Manitoba 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                                      
Alberta 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                                      
Yukon Territory 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                                      
Nunavut 0 0 0 0 0 0 0 0 0 0 0 0                                      
Total 0 0 0 0 0 0 0 0 0 0 0 1Table 1 Footnote 1                                      
TABLE 2: West Nile Virus human clinical cases and asymptomatic infections by Province/Territory for the current report week and year to date, 2015 season
  Week 28: July 12 to July 18, 2015
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 infectionTable 2 Footnote 3

Table 2 Footnotes

Table 2 Footnote 1

Total clinical cases are  the sum of both probable and confirmed: West Nile virus neurological and non-neurological syndromes, along with any unclassified or unspecified cases.

Return to table 2 footnote 1 referrer

Table 2 Footnote 2

Likely related to travel outside the Province/Territory. These cases are included in either the total clinical cases or West Nile virus asymptomatic infections.

Return to table 2 footnote 2 referrer

Table 2 Footnote 3

Satisfies West Nile virus 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 West Nile virus specific nucleic acid amplification test following any positive donor screen test result.

Return to table 2 footnote 3 referrer

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 1 1 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 1 1 0 0
  Year to date: January 1 to July 18, 2015
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 1 1 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 1 1 0 0

FIGURE 2: West Nile Virus clinical cases and asymptomatic infections by report week for selected years

text description in table 3 below
* 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
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

Table 3 Footnotes

Table 3 Footnote *

One of these cases was likely exposed prior to the 2014 West Nile virus season.

Return to table 3 footnote * referrer

2015 0 0 0 0 0 0 0 0 0 0 0 1                                      
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 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: Number of West Nile Virus mosquito pools tested weekly by Province/Territory - 2015 season Table 4.1 Footnote 1
  Report week of 2015
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

Table 4.1 Footnotes

Table 4.1 Footnote 1

Detailed West Nile virus mosquito surveillance data can be accessed through Provincial/Territorial websites.

Return to table 4.1 footnote 1 referrer

Table 4.1 Footnote 2

Exact number of tested mosquito pools to be determined.

Return to table 4.1 footnote 2 referrer

Newfoundland and Labrador 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                                      
New Brunswick 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                                      
Quebec 0 0 0 0 0 0 0 0 0 120 115 0                                      
Ontario 0 0 0 0 0 0 0 1Table 4.1 Footnote 2 0 0 0 1Table 4.1 Footnote 2                                      
Manitoba 0 0 0 0 12 4 87 82 44 75 73 132                                      
Saskatchewan 0 0 0 0 2 0 3 3 10 13 15 38                                      
Alberta 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                                      
Yukon Territory 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                                      
Nunavut 0 0 0 0 0 0 0 0 0 0 0 0                                      
Total 0 0 0 0 14 4 90 86 54 208 203 171                                      
TABLE 4.2: Number of mosquito pools tested and number of positive mosquito pools by Province/Territory, 2015 season
  Year to date: January 1 to July 18, 2015
Number of positive mosquito pools Number of mosquito pools tested Percentage of positive mosquito pools (%)

Table 4.2 Footnotes

Table 4.2 Footnote 1

The number of tested mosquito pools to be determined.

Return to table 4.2 footnote 1 referrer

Quebec 0 235 0
Ontario 2 N/ATable 4.2 Footnote 1 N/ATable 4.2 Footnote 1
Manitoba 1 509 0.20
Saskatchewan 1 84 1.19
Total 4 828 0.48

FIGURE 3: Reported number of dead birds testing positive for West Nile Virus by Province/Territory and by report week, 2015 season*

text description in table 5 below

Number of Provinces/Territories are no longer conducting dead bird surveillance as part of their West Nile Virus (WNV) program.

As part of their national network to monitor the health of wildlife in Canada, the Canadian Wildlife Health Cooperative (CWHC) receives dead bird submissions for analysis. As part of this work, and if appropriate, the CWHC will test some of these dead birds for infection with WNV. Results from this program are recorded in the table above, and are also available on the CWHC web site at: http://www.cwhc-rcsf.ca/data_products_wnv.php

* Data from the Canadian Wildlife Health Cooperative. You may also access historical dead bird surveillance test results via this link.

TABLE 5: Reported number of dead birds testing positive for West Nile Virus by Province/Territory and by report week, 2015 season Table 5 Footnote *
  Report week of 2015
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

Table 5 Footnotes

Table 5 Footnote *

Data from the Canadian Wildlife Health Cooperative. You may also access historical dead bird surveillance test results via this link.

Return to table 5 footnote * referrer

Newfoundland and Labrador 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
New Brunswick 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
Quebec 0 0 0 0 0 0 0 0 0 0 0 0                                       0
Ontario 0 0 0 0 0 0 0 1 0 0 0 0                                       1
Manitoba 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
Alberta 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
Yukon Territory 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
Nunavut 0 0 0 0 0 0 0 0 0 0 0 0                                       0
Total 0 0 0 0 0 0 0 1 0 0 0 0                                       1

FIGURE 4: Percentage of dead birds testing positive for West Nile Virus in the 2015 season by report week, as compared to the 2003, 2012 and 2014 seasons

text description in table 6 below
TABLE 6: Percentage of dead birds testing positive for West Nile Virus in the 2015 season by report week, as compared to the 2003, 2012 and 2014 seasons

 

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

Table 6 Footnotes

Table 6 Footnote *

Data became available during Week 30; this is a cumulative number of dead birds tested from Week 1 to Week 30.

Return to table 6 footnote * referrer

Numbers positive 2015 0 0 0 0 0 0 0 1 0 0 0 0                                      
Numbers tested 2015 0 0 0 0 0 0 0 1 0 0 1 0                                      
Percentage positive 2015 0 0 0 0 0 0 0 100 0 0 0 0                                      
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 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 3 1 4 2 1 0 0 0 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 20 100 0 25 0 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
Report a problem or mistake on this page
Please select all that apply:

Thank you for your help!

You will not receive a reply. For enquiries, contact us.

Date modified: