Low levels of influenza activity continue to be reported in Canada; no new laboratory detections reported this week
During week 41, influenza activity in Canada remained low with the majority of the influenza surveillance regions reporting no activity and only six regions (in NS, QC, ON & AB) reported sporadic influenza activity (see map). No specimens tested positive for influenza in Canada this week (percentage positive = 0%; 0/1,167) (see table). In week 41, the ILI consultation rate was 18 ILI consultations per 1,000 patient visits (see ILI graph), and is within the expected range for this week. The sentinel response rate has been slowly increasing over the last several weeks but remained low at 47% for this week. Fluctuations in ILI consultation rates are expected during periods of low influenza activity and low sentinel participation. No new influenza outbreaks were reported in week 41.

Antigenic Characterization & Antiviral Resistance:
Since 1 September 2008, National Microbiology Laboratory (NML) has antigenically characterized three influenza viruses: one influenza A/Brisbane/59/2007(H1N1)-like and two influenza B/Florida/4/2006 viruses, which are the influenza A(H1N1) and influenza B components recommended for the 2008-09 influenza vaccine (see pie chart).

Antiviral Resistance:
The testing results showed that the influenza A(H1N1) isolate was sensitive to amantadine, however, it was resistant to oseltamivir due to the H274Y mutation. Both of the influenza B viruses tested were found to be sensitive to oseltamivir.

Influenza-associated Paediatric Hospitalizations:
No laboratory-confirmed influenza-associated paediatric hospitalizations have been reported through the Immunization Monitoring Program Active (IMPACT) network for the 2008-09 season.

International:

WHO: During the weeks 39 and 40, overall influenza activity in the southern hemisphere continued to decline. Activity was low in the rest of the world.

• WHO

CDC: During week 40, overall influenza activity was low with the majority of the states reporting no activity and only 7 states reported sporadic activity. Of the 1,123 specimens tested for influenza viruses in week 40, 8 (0.7%) were positive. From May 18 - September 27, 2008, the CDC antigenically characterized 6 influenza viruses: 4 influenza A(H1), 1 influenza A(H3), and 1 influenza B. All six viruses are antigenically similar to the components selected for the 2008-09 influenza vaccine. CDC performed oseltamivir and zanamivir resistance testing on 10 influenza A and B viruses collected since May 18. Two of the 6 influenza A(H1N1) viruses tested were found to be resistant to oseltamivir and the influenza A(H3N2) and influenza B viruses tested were sensitive to oseltamivir. All tested viruses retain their sensitivity to zanamivir. Of the 6 influenza A viruses collected since May 18 that were tested for adamantane resistance, 1 influenza A(H3N2) virus and 1 of the 5 influenza A (H1N1) viruses tested were resistant.

• CDC

EISS: In week 41, levels of influenza activity in Europe were low, with all countries reporting no or only sporadic influenza activity. Since week 40, 13 influenza viruses were detected of which 8 were influenza A not subtyped, 2 were influenza A(H1), 2 were influenza A(H3) and 1 was influenza B. It is currently too early to determine which virus type or subtype may become dominant in Europe this season.

• EISS

Human Avian Influenza: No new cases of human H5N1 avian influenza infection have been reported by the WHO since 10 September 2008.

• WHO

 

Recommended composition of influenza virus vaccines for use in the 2009 southern hemisphere influenza season:
It is recommended that vaccines for use in the 2009 influenza season (southern hemisphere winter) contain the following:

• an A/Brisbane/59/2007 (H1N1)-like virus
• an A/Brisbane/10/2007 (H3N2)-like virus
• a B/Florida/4/2006-like virus

 

• WHO

 

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Total number of influenza tests performed and number of positive tests by province/territory of testing laboratory, Canada, 2008-2009

Province of reporting laboratories	Report Period: October 5, 2008 to October 11, 2008				Season to Date: August 24, 2008 to October 11, 2008
	Total # Influenza Tests	# of Positive Tests			Total # Influenza Tests	# of Positive Tests
		Influenza A	Influenza B	Total		Influenza A	Influenza B	Total
NL	5	0	0	0	24	0	0	0
PE	5	0	0	0	11	0	0	0
NS	11	0	0	0	59	1	0	1
NB	3	0	0	0	32	0	0	0
QC	292	0	0	0	1323	2	0	2
ON	423	0	0	0	1898	0	2	2
MB	32	0	0	0	254	0	0	0
SK	52	0	0	0	415	0	0	0
AB	319	0	0	0	2023	1	3	4
BC	25	0	0	0	120	0	0	0
Canada	1167	0	0	0	6159	4	5	9

 

Specimens from NT, YT, and NU are sent to reference laboratories in other provinces.

Note: Cumulative data includes updates to previous weeks; due to reporting delays, the sum of weekly report totals do not add up to cumulative totals.

Abbreviations: Newfoundland/Labrador (NL), Prince Edward Island (PE), New Brunswick (NB), Nova Scotia (NS), Quebec (QC), Ontario (ON), Manitoba (MB), Saskatchewan (SK), Alberta (AB), British Columbia (BC), Yukon (YT), Northwest Territories (NT), Nunavut (NU)

Respiratory virus laboratory detections in Canada, by geographic regions, are available weekly on the following website:
<http://www.phac-aspc.gc.ca/bid-bmi/dsd-dsm/rvdi-divr/index-eng.php>

Number of influenza surveillance regions† reporting widespread or localized influenza activity, Canada, by report week, 2008-2009 (N=54)

† sub-regions within the province or territory as defined by the provincial/territorial epidemiologist. Graph may change as late returns come in.

Influenza Activity Level by Provincial and Territorial Influenza Surveillance Regions, Canada, October 5, 2008 to October 11, 2008 (Week 41)
	No Data No Activity Sporadic Activity Localized Activity Widespread Activity

Note: Influenza activity levels, as represented on this map, are assigned and reported by Provincial and Territorial Ministries of Health, based on laboratory confirmations, sentinel ILI rates (see graphs and tables) and outbreaks. Please refer to detailed definitions. For areas where no data is reported, late reports from these provinces and territories will appear on the FluWatch website. Select single maps by report week to get this updated information.
<http://dsol-smed.phac-aspc.gc.ca/dsol-smed/fluwatch/fluwatch.phtml?lang=e>

Click on the map to view provinces/territories and maps for other weeks.

Influenza tests reported and percentage of tests positive, Canada, by report week, 2008-2009

Percent positive influenza tests, compared to other respiratory viruses, Canada, by reporting week, 2008-2009

Influenza strain characterization, Canada, cumulative, 2008-2009 influenza season by the Respiratory Viruses Section at the National Microbiology Laboratory
[N=3]

{Strain characterization, number identified, per cent of total number}

NACI recommends that the trivalent vaccine for the 2008-2009 season in Canada contain A/Brisbane/59/2007 (H1N1)-like virus; an A/Brisbane/10/2007 (H3N2)-like virus; and a B/Florida/4/2006-like virus.

Influenza-like illness (ILI) consultation rates, Canada, by report week, 2008-2009 compared to 1996/97 through to 2006/07 seasons

Note: No data available for mean rate in previous years for weeks 19 to 39 (1996-1997 through 2002-2003 seasons).

Number of New Outbreaks in Long Term Care Facilities, Canada, by Report Week, 2008-2009

Please note that the above graphs may change as late returns come in.

Single Maps | Dual Maps | Animated Maps | FluWatch Reports

Definitions for the 2008-2009 season