Mosquito-borne diseases surveillance report: August 16 to August 29, 2021 (Week 33 to 34)
Organization: Public Health Agency of Canada
Date published: 2021-09-13
As of surveillance week 34, ending on August 29, 2021, four clinical human cases and one asymptomatic human case of West Nile virus (WNV) have been reported to the Public Health Agency of Canada (PHAC) (Table 1).
|Province||Clinical cases||Total of clinical cases Footnote 1||Asymptomatic infections Footnote 2||YTD grand total||Rate (per 100,000) Footnote 3|
Mosquito, wild bird and equine epidemiology
As of week 34, PHAC has been notified of 13,590 mosquito pools tested for WNV in Canada. Of these, there have been 2 WNV-positive mosquito pools identified in Québec, 67 Ontario, 116 in Manitoba and 9 in Saskatchewan (Table 2).
Eight wild birds have tested positive WNV by the by the Canadian Wildlife Health Cooperative, 5 in Québec and 3 in Ontario (Table 3). The province of Manitoba reported two birds tested positive for WNV.
Since the start of this season, the Canadian Food Inspection Agency (CFIA) has identified four equine cases that tested positive for WNV in Saskatchewan and five in Manitoba (Table 3).
Figure 2 - Legend
Human cases includes clinical cases and asymptomatic infection.
Episode week is based on symptom onset or best available date including: diagnosis, lab sample or date reported.
Episode week is based off date of death or best available date including: date found, submitted, or received.
|ProvinceFootnote 1||Positive pools||Total pools tested||Percent positive|
|Province||Wild birds Footnote 1||Equine|
As of August 29th, 2021, one human case of California serogroup virus was diagnosed by the National Microbiology Laboratory in Canada: Ontario (1). The case was further classified as Jamestown Canyon virus.
Eastern equine encephalitis
No human cases of Eastern Equine Encephalitis virus (EEEV) have been reported to PHAC since the beginning of the 2021 transmission season.
The CFIA has reported one horse case testing positive for Eastern Equine Encephalitis virus (EEEV) in Ontario.
Provincial/territorial and international surveillance links
Data reported to PHAC is subject to change and may differ from provincial webpages due to reporting timelines. To obtain the latest arbovirus surveillance data, please refer to the following jurisdictional/regional webpages:
Thank you to all our partners for participating in the National WNV/MBD surveillance program.
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