West Nile Virus national surveillance report: September 16 to 22, 2018

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Organization: Public Health Agency of Canada
Published: October 15, 2018
ISBN: 2368-2841
Related Topics
West Nile Virus - Week 38 2018
Canada
- Human
During surveillance week 38, ending on September 22, 2018, 56 clinical cases of West Nile virus (WNV) were retrospectively reported to the Public health Agency of Canada (PHAC). A number of other possible infections remain under investigation.
As of week 38, a total of 216 clinical cases of WNV have been reported by the following four provinces: Alberta (37), Manitoba (29), Ontario (88), and Québec (62). Of these, 98 (45%) have been classified as WNV neurological syndrome, 71 (33%) as WNV non-neurological syndrome and 47 (22%) as unspecified. Nine deaths have been reported. In addition, 18 WNV asymptomatic infections have been reported: Alberta (5), Manitoba (3), Ontario (5), and Québec (5).
- Mosquito
-
To date (week 38), the PHAC has been notified of 16,814 mosquito pools tested for WNV: Saskatchewan (761), Manitoba (1,924), Ontario (12,581), and Québec (1,548). Of these, 561 (3.34%) pools have tested positive for WNV: 50 in Saskatchewan, 168 in Manitoba, 304 in Ontario, and 39 in Québec.
- Wild Bird
-
To date, eighty-seven out of 177 dead wild birds have tested positive for WNV by the Canadian Wildlife Health Cooperative (CWHC), Manitoba Agriculture and British Columbia Ministry of Agriculture-Animal Health Centre: British Columbia (2), Saskatchewan (3), Manitoba (14), Ontario (28), and Québec (40). In addition, 12 live wild birds in Québec have tested positive for WNV by the University of Montréal.
- Equine
-
The Canadian Food Inspection Agency (CFIA) has reported 109 horses with West Nile fever in the following five provinces: British Columbia (1), Alberta (68), Saskatchewan (30), Manitoba (6), and Ontario (4).
United States and U.S. territories
As of September 18th, 1,077 human cases of WNV have been reported to the US Centers for Disease Control and Prevention (CDC). Of these 608 (56%) were classified as neuroinvasive disease and 469 (44%) as non-neuroinvasive disease. Thirty-five deaths have been reported. In addition, 196 presumptive viremic blood donors have been identified.
Europe and Neighboring Countries
As of September 27th, 1,670 human cases of West Nile fever have been reported to the European Centre for Disease Prevention and Control. One hundred and twenty-four deaths have been reported.
Weekly updates: 2018 West Nile fever transmission season.
Other Mosquito-borne Diseases in Canada - Week 38 2018
- Eastern Equine Encephalitis virus
-
The CFIA has reported 11 horses testing positive for Eastern Equine Encephalitis virus (EEEV) in Ontario. No human cases of EEEV have been reported to the PHAC during the 2018 season.
- California Serogroup virus
-
Since May 1, 2018, 23 human cases/exposures of California serogroup virus have been reported by the National Microbiology Laboratory in the following seven provinces: Alberta (1), Saskatchewan (4), Manitoba (1), Ontario (5), Quebec (5), New Brunswick (5), and Nova Scotia (2). Additional work to further type these as Jamestown Canyon virus or Snowshoe hare virus is on-going.
Figure and tables

Figure 1 - Text description
Map showing geographic distribution of human cases of West Nile virus (WNV) in Canada.
As of September 22, 2018, 216 human cases associated with WNV in Canada have been reported to the Public Health Agency of Canada (PHAC).

- Footnote ±
-
WNV 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.
- Footnote *
-
WNV likely acquired while travelling outside of Canada.
*
Figure 2 - Text description
As of week 38, ending September 22, 2018, there are 216 human clinical cases and asymptomatic infections associated with WNV in Canada.
Province / Territory | Report Weekfigure 2 table note ± | Total | |||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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 | ||
Alberta | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 6 | 12 | 14 | 7 | 2 | 0 | 0 | - | - | - | - | - | - | - | - | - | 42 |
Manitoba | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 2 | 1 | 5 | 10 | 6 | 3 | 4 | 0 | 0 | - | - | - | - | - | - | - | - | - | 32 |
Ontario | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 4 | 4 | 6 | 9 | 17 | 17 | 13 | 13 | 8 | 0 | - | - | - | - | - | - | - | - | - | 93 |
Quebec | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 7 | 10 | 15 | 7 | 12 | 7 | 1 | 0 | - | - | - | - | - | - | - | - | - | 67 |
Total | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 6 | 7 | 15 | 30 | 54 | 50 | 35 | 26 | 9 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 234 |
'-' = Not available. Figure 2 table notes
|

Figure 3 note ±: WNV 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.
Figure 3 - Text description
Year | Report Weekfigure 3 table note ± | Total | |||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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 | ||
2018 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 5 | 7 | 15 | 30 | 54 | 50 | 35 | 26 | 9 | 0 | - | - | - | - | - | - | - | - | - | 234 |
2017 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 1 | 7 | 3 | 8 | 10 | 26 | 31 | 31 | 27 | 13 | 16 | 7 | 8 | 4 | 1 | 1 | 3 | 0 | 0 | 0 | 200 |
2016 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 5 | 5 | 14 | 11 | 16 | 12 | 9 | 6 | 15 | 5 | 0 | 0 | 3 | 1 | 0 | 1 | 0 | 105 |
2014 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 4 | 3 | 5 | 6 | 1 | 1 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 22 |
2012 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 3 | 5 | 11 | 16 | 27 | 53 | 63 | 57 | 43 | 43 | 45 | 24 | 30 | 14 | 9 | 5 | 1 | 0 | 0 | 0 | 0 | 450 |
2007 | 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 | 2,378 |
2003 | 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 | 1,450 |
'-' = Not available. Figure 3 table notes
|
Province/Territory | Clinical Cases | Total clinical casestable 1 note 1 | Total travel-related casestable 1 note 2 | Total asymptomatic infectionstable 1 note 3 | ||
---|---|---|---|---|---|---|
Neurological syndrome | Non-neurological syndrome | Unclassified/ Unspecified | ||||
Report week 38: September 16 to September 22, 2018 | ||||||
British Columbia | 0 | 0 | 0 | 0 | 0 | 0 |
Alberta | 0 | 0 | 0 | 0 | 0 | 0 |
Saskatchewantable 1 note 4 | 0 | - | - | - | - | - |
Manitoba | 0 | 0 | 0 | 0 | 0 | 0 |
Ontario | 0 | 0 | 0 | 0 | 0 | 0 |
Québec | 0 | 0 | 0 | 0 | 0 | 0 |
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 |
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 September 22, 2018 | ||||||
British Columbia | 0 | 0 | 0 | 0 | 0 | 0 |
Alberta | 5 | 32 | 0 | 37 | 7 | 5 |
Saskatchewantable 1 note 4 | 0 | - | - | - | - | - |
Manitoba | 3 | 3 | 23 | 29 | 0 | 3 |
Ontario | 40 | 24 | 24 | 88 | 2 | 5 |
Québec | 50 | 12 | 0 | 62 | 2 | 5 |
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 |
Yukon Territory | 0 | 0 | 0 | 0 | 0 | 0 |
Northwest Territory | 0 | 0 | 0 | 0 | 0 | 0 |
Nunavut | 0 | 0 | 0 | 0 | 0 | 0 |
Total | 98 | 71 | 47 | 216 | 11 | 18 |
'-' = Not available. Table 1 notes
|
Province / Territory | Number of positive mosquito pools | Number of mosquito pools tested | Percentage of positive mosquito pools (%) |
---|---|---|---|
Saskatchewan | 50 | 761 | 6.57 |
Manitoba | 168 | 1,924 | 8.73 |
Ontario | 304 | 12,581 | 2.42 |
Québec | 39 | 1,548 | 2.52 |
Total | 561 | 16,814 | 3.34 |
Table 2 notes
|
Province / Territory | Report Week | Total | ||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | ||
Saskatchewan | 0 | 15 | 18 | 17 | 45 | 55 | 90 | 104 | 96 | 106 | 62 | 65 | 52 | 26 | 10 | 0 | - | - | - | 761 |
Manitoba | 15 | 39 | 89 | 107 | 124 | 122 | 241 | 240 | 247 | 169 | 172 | 163 | 113 | 39 | 29 | 15 | - | - | - | 1,924 |
Ontario | 0 | 0 | 0 | 0 | 842 | 955 | 1,024 | 963 | 1,073 | 1,059 | 1,156 | 1,124 | 1,133 | 998 | 920 | 667 | 667 | - | - | 12,581 |
Québec | 0 | 69 | 77 | 105 | 105 | 113 | 109 | 109 | 110 | 99 | 123 | 122 | 102 | 103 | 122 | 80 | - | - | - | 1,548 |
Total | 15 | 123 | 184 | 229 | 1,116 | 1,245 | 1,464 | 1,416 | 1,526 | 1,433 | 1,513 | 1,474 | 1,400 | 1,166 | 1,081 | 762 | 667 | - | - | 16,814 |
'-' = Not available. Table 3 notes
|

Figure 4 notes
- Figure 4 note *
-
Not all provinces conduct dead wild bird surveillance as part of their respective WNV surveillance program. However, WNV positive dead wild birds may be identified through the National Wildlife Disease Surveillance Program, CWHC or by specific provinces.
- Figure 4 note ‡
-
WNV positive birds are grouped by report week, based on best date available. Best date could include one of the following: date found, date of death, date submitted, or date received.
Figure 4 - Text description
As of week 38, ending September 22, 2018, there are 87 WNV cases in birds in Canada.
Province | Jun | Jul | Aug | Sept | Oct | Nov | Total | |||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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 | 48 | ||
British Columbia | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 0 | 0 | 0 | 0 | 0 | - | - | - | - | - | - | - | - | - | - | 2 |
Saskatchewan | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | - | - | - | - | - | - | - | - | - | - | 3 |
Manitoba | 0 | 0 | 0 | 0 | 3 | 0 | 0 | 0 | 0 | 7 | 0 | 3 | 1 | 0 | 0 | 0 | 0 | - | - | - | - | - | - | - | - | - | - | 14 |
Ontario | 0 | 0 | 0 | 0 | 0 | 2 | 0 | 3 | 5 | 3 | 8 | 4 | 2 | 0 | 0 | 1 | 0 | - | - | - | - | - | - | - | - | - | - | 28 |
Québec | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 3 | 10 | 10 | 5 | 1 | 5 | 2 | 1 | - | - | - | - | - | - | - | - | - | - | 40 |
Total | 0 | 0 | 0 | 0 | 3 | 2 | 1 | 4 | 8 | 13 | 18 | 19 | 9 | 1 | 5 | 3 | 1 | - | - | - | - | - | - | - | - | - | - | 87 |
'-' = Not available. |
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