FluWatch report: September 9, 2018 to September 22, 2018 (Week 37-38)

Overall Summary

  • Influenza activity remains at interseasonal levels across the country.
  • The majority of regions in Canada report no influenza activity.
  • All indicators of influenza activity are at low levels, as expected for this time of year.
  • Influenza A is the most common influenza virus circulating in Canada.
  • Influenza and other respiratory viruses are monitored weekly and results reported every Thursday in the Respiratory Virus Detections in Canada Report

Influenza/Influenza-like Illness Activity (geographic spread)

During week 38, the following influenza activity levels were reported (Figure 1):

  • Localized activity was reported in one region in Ontario.
  • Sporadic activity was reported by 6 regions, in B.C(1), Alberta(2), Saskatchewan(1), Ontario(1) and Quebec(1).
  • No activity was reported by the majority of regions (43).
  • No data were reported by three regions.

thumbnail

Download the alternative format
(PDF format, 896 KB, 6 pages)

Organization: Public Health Agency of Canada

Date published: 2018-09-28

Figure 1 – Map of overall influenza/ILI activity by province and territory, Canada, week 2018-38

Figure 1
Figure 1 - Text Description
Figure 1 – Map of overall influenza/ILI activity level by province and territory, Canada, week 2018-38
Influenza Surveillance Region Activity Level
Newfoundland - Central  No Activity
Newfoundland - Eastern  No Activity
Grenfell Labrador No Activity
Newfoundland - Western  No Activity
Prince Edward Island No Activity
Nova Scotia - Central (Zone 4) No Activity
Nova Scotia - Western (Zone 1) No Activity
Nova Scotia - Northern (Zone 2) No Activity
Nova Scotia - Eastern (Zone 3) No Activity
New Brunswick - Public Health Region 1 No Activity
New Brunswick - Public Health Region 2 No Activity
New Brunswick - Public Health Region 3 No Activity
New Brunswick - Public Health Region 4 No Activity
New Brunswick - Public Health Region 5 No Activity
New Brunswick - Public Health Region 6 No Activity
New Brunswick - Public Health Region 7 No Activity
Nord-est Québec No Activity
Québec et Chaudieres-Appalaches No Activity
Centre-du-Québec No Activity
Montréal et Laval Sporadic
Ouest-du-Québec No Activity
Montérégie  No Activity
Ontario - Central East Localized
Ontario - Central West Sporadic
Ontario - Eastern No Activity
Ontario - North East No Activity
Ontario - North West  No Activity
Ontario - South West  No Activity
Ontario - Toronto No Activity
Manitoba - Interlake-Eastern  No Activity
Manitoba - Northern Regional No Activity
Manitoba - Prairie Mountain No Activity
Manitoba - South No Activity
Manitoba - Winnipeg No Activity
Saskatchewan - North  No Activity
Saskatchewan - Central No Activity
Saskatchewan - South Sporadic
Alberta - North Zone Sporadic
Alberta - Edmonton No Activity
Alberta - Central Zone  No Activity
Alberta - Calgary Sporadic
Alberta - South Zone  No Activity
British Columbia - Interior No Activity
British Columbia - Fraser  No Activity
British Columbia - Vancouver Coastal Sporadic
British Columbia - Vancouver Island No Activity
British Columbia - Northern No Activity
Yukon No Activity
Northwest Territories - North No Activity
Northwest Territories - South No Activity
Nunavut - Baffin No Data
Nunavut - Kivalliq No Data
Nunavut - Kitimeot No Data

Laboratory Confirmed Influenza Detections

In weeks 37 and 38, the following results were reported from sentinel laboratories across Canada (Figure 2 and Figure 3):

  • Overall, laboratory detections of influenza are at interseasonal levels.
  • A total of 23 laboratory detections of influenza were reported, which is similar to the previous 2-week period. Twenty of these detections were influenza A.
  • The percentage of tests positive for influenza was 0.42% and  0.58% in weeks 37 and 38 respectively

To date this season, detailed information on age and type/subtype has been received for 36 laboratory-confirmed influenza cases (Table 1).

  • Adults 20-64 years of age represent the largest proportion of cases overall (72%)

For more detailed weekly and cumulative influenza data, see the text descriptions for Figures 2 and 3 or the Respiratory Virus Detections in Canada Report.

Figure 2 – Number of positive influenza tests and percentage of tests positive, by type, subtype and report week, Canada, 2018-19, weeks 35 to 38

Figure 2

The shaded area indicates weeks where the positivity rate was at least 5% and a minimum of 15 positive tests were observed, signalling the start and end of seasonal influenza activity.

Figure 2 - Text Description
Figure 2 - Number of positive influenza tests and percentage of tests positive, by type, subtype and report week, Canada, 2018-19
Report Week A(Unsubtyped) A(H3) A(H1)pdm09 Influenza B
35 3 2 7 0
36 4 7 4 0
37 3 2 3 1
38 6 3 2 3

Figure 3 – Cumulative numbers of positive influenza specimens by type/subtype and province/territory, Canada, weeks 2018-35 to 2018-38

Figure 3
Figure 3 - Text Description
Figure 3 - Cumulative numbers of positive influenza specimens by type/subtype and province/territory, Canada, 2018-19
Reporting
provincesTable Figure 3 - Footnote 1
Week (September 9, 2018 to September 22, 2018) Cumulative (August 26, 2018 to September 22, 2018)
Influenza A B Influenza A B A & B
Total
A
Total
A
(H1N1)pdm09
A
(H3N2)
A(UnS)Table Figure 3 - Footnote B
Total
A
Total
A
(H1N1)pdm09
A
(H3N2)
A(UnS)Table Figure 3 - Footnote B
Total
BC 4 3 1 0 0 10 4 2 4 0 10
AB 4 0 1 3 1 13 3 5 5 1 14
SK 4 0 2 2 0 4 0 2 2 0 4
MB 0 0 0 0 0 0 0 0 0 0 0
ON 3 2 0 1 3 16 9 5 2 3 19
QC 1 0 0 1 0 3 0 0 3 0 3
NB 0 0 0 0 0 0 0 0 0 0 0
NS 0 0 0 0 0 0 0 0 0 0 0
PE 0 0 0 0 0 0 0 0 0 0 0
NL 0 0 0 0 0 0 0 0 0 0 0
YT 0 0 0 0 0 0 0 0 0 0 0
NT 0 0 0 0 0 0 0 0 0 0 0
NU 0 0 0 0 0 0 0 0 0 0 0
Canada 16 5 4 7 4 46 16 14 16 4 50
PercentageTable Figure 3 - Footnote 2 80% 31% 25% 44% 20% 92% 35% 30% 35% 8% 100%
Table Figure 3 - Footnote 1

Specimens from NWT, YT, and Nvt are sent to reference laboratories in other provinces.

Return to Table Figure 3 - Footnote 1 referrer

Table Figure 3 - Footnote 2

Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.

Return to Table Figure 3 - Footnote 2 referrer

Table Figure 3 - Footnote UnS

Unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.

Return to first Table Figure 3 - Footnote UnS referrer

Discrepancies in values in Figures 2 and 3 may be attributable to differing data sources.

Cumulative data includes updates to previous weeks.

Table 1 - Cumulative numbers of positive influenza specimens by type, subtype and age-group reported through case-based laboratory reporting, Canada, weeks 2018-35 to 2018-38
Age groups (years) Cumulative (August 26, 2018 to September 22, 2018)
Influenza A B Influenza A and B
A Total A(H1) pdm09 A(H3) A (UnS)Footnote 1 Total # %
0-4 - 0 <5 <5 0 - -
5-19 - 0 0 <5 0 - -
20-44 - 5 0 <5 <5 - -
45-64 - 7 <5 5 <5 - -
65+ - <5 <5 <5 <5 - -
Total - >12 7 12 <5 - -
Tableau 1 - Note 1

UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available;

Return to Table 1 - Note 1

Syndromic/Influenza-like Illness Surveillance

Healthcare Professionals Sentinel Syndromic Surveillance

In week 38, 0.7% of visits to healthcare professionals were due to influenza-like illness (ILI) (Figure 4). The percentage of visits for ILI is at interseasonal levels.

Figure 4 - Percentage of visits for ILI reported by sentinels by report week, Canada, weeks 2018-35 to 2018-38 Number of Sentinels Reporting in Week 38: 71

The shaded area represents the maximum and minimum percentage of visits for ILI reported by week from seasons 2012-13 to 2016-17

Figure 4
Figure 4 - Text Description
Report week 2018-19 Average Min Max
35 0,6% 0,8% 0,5% 1,2%
36 0,7% 0,8% 0,7% 1,0%
37 0,5% 0,9% 0,7% 1,0%
38 0,7% 1,1% 1,0% 1,4%

Participatory Syndromic Surveillance

FluWatchers is a participatory ILI surveillance system that relies on weekly voluntary submissions of syndromic information from Canadians across Canada. To learn more about the FluWatchers program.

If you are interested in becoming a FluWatcher for the 2018-19 season, sign up today.

The 2018-19 FluWatchers reporting season will begin October 1st, 2018 (week 40).

Influenza Outbreak Surveillance

In weeks 37 and 38, no new influenza outbreaks were reported. Three ILI outbreaks were reported in week 38.

Severe Outcomes Influenza Surveillance

Provincial/Territorial Influenza Hospitalizations and Deaths

In weeks 37 and 38 fewer than five influenza-associated hospitalizations were reported by participating provinces and territoriesFootnote 1.

Pediatric Influenza Hospitalizations and Deaths

Surveillance of laboratory-confirmed influenza associated pediatric (≤16 years of age) hospitalizations from the Immunization Monitoring Program Active (IMPACT) network has not yet begun for the 2018-19 season.

Adult Influenza Hospitalizations and Deaths

Surveillance of laboratory-confirmed influenza-associated adult (≥16 years of age) hospitalizations by the Canadian Immunization Research Network (CIRN) Serious Outcomes Surveillance (SOS) network has not yet begun for the 2018-19 season.

Influenza Strain Characterizations

The National Microbiology Laboratory has not yet reported influenza strain characterization results for influenza viruses collected during the 2018-19 season.

Antiviral Resistance

The National Microbiology Laboratory has not yet reported antiviral resistance results for influenza viruses collected during the 2018-19 season.

Notes: To learn more about definitions, descriptions and the FluWatch program in general, see the Overview of influenza monitoring in Canada page. For more information on the flu, see our Flu(influenza) web page.

This report is available on the Government of Canada Influenza webpage.
Ce rapport est disponible dans les deux langues officielles.

We would like to thank all the Fluwatch surveillance partners who are participating in this year's influenza surveillance program.

Page details

Date modified: