Canada:
Widespread activity reported in the Interior of BC and throughout Ontario, with 23 outbreaks in Ontario LTCFs. Localized or sporadic activity in all other provinces and territories, except Newfoundland and Labrador. Across Canada, during the week ending December 13 (week 50), sentinel physicians reported 52 cases of influenza-like illness (ILI) per 1000 patient visits, which is within the baseline rate for this time of year (see ILI graph). Health Canada received 3,983 reports of laboratory tests for influenza, including 691 (17%) influenza A detections and 0 (0%) influenza B detections (see table below). The National Microbiology Laboratory has antigenetically characterized 294 influenza viruses to date; 267 (91%) A/Fujian/411/02(H3N2)-like, 25 (8.5%) A/Panama/2007/99(H3N2)-like, 1(0.3%) A/NewCaledonia/20/99(H1N1)-like and 1(0.3%) H1N2. Detections of other respiratory viruses are at or below the expected range for this time of year. To date, there have been a total of 210 outbreaks, including LTCF/retirement lodges (119), hospitals (13) and schools (78), with a sharp increase in week 50 due to 23 new outbreaks reported in Ontario. British Columbia has reported two deaths in children that may be associated with influenza, however, laboratory confirmation is still pending. Current data in Canada, the U.S. and globally indicate that the impact of A/Fujian is still within the expected range observed for previous severe flu seasons.

United States:
CDC: During the week ending December 6, 2003 (week 49), widespread or regional activity was reported by the majority of US states (39), with local or sporadic activity reported by the remainder. ILI visits accounted for 5.1% of patient visits to sentinel physicians, which is above the national baseline of 2.5%. Sentinel cities reported 7.0% of deaths attributable to pneumonia and influenza, which is below the epidemic threshold of 7.6% for this week. The CDC received 3,834 specimens for influenza testing; 1,409 (36.8%) were positive. A total of 212 influenza A(H3N2) isolates have been characterized to date; 54 (25%) were antigenically similar to the vaccine strain A/Panama/2007/99 and 158 (75%) were similar to the new drift variant A/Fujian/411/2002.
For details of the 2003-04 influenza season in the US to date, with details on severe illness and deaths, see
MMWR: <http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5249a1.htm>
CDC: <http://www.cdc.gov/ncidod/diseases/flu/weekly.htm>

International:
WHO/EISS summary: Influenza activity associated with influenza A(H3N2) viruses continues to rise substantially in some countries in Europe (Finland, France, Norway, Russian Federation and Switzerland ), but has declined in the UK, Portugal and Spain. An increasing trend has also been observed in a number of other European countries (Denmark, Italy and Ukraine) where influenza activity currently remains low. Most outbreaks to date have been due to A/Fujian/411/2002(H3N2)-like viruses with some due to A/Panama/2007/99(H3N2)-like viruses and to a lesser extent other viruses. So far, there have been very few reports of influenza A/Fujian/411/2002-like virus being detected in Asia.
SARS: An isolated case of SARS associated with a laboratory exposure has been reported in Taiwan. Stringent precautionary public health and infection control measures have been implemented and to date an intensive investigation has found no evidence of further spread from this case.
GPHIN – media are reporting high levels of influenza activity in Moscow, Romania and the north east of China.
EISS: <http://www.eiss.org>
WHO: <http://www.who.int/csr/don/2003_12_17a/en/>

Total number of influenza tests performed and number of positive tests by province/territory of testing laboratory, Canada, 2003-2004

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 (NF), 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.hc-sc.gc.ca/pphb-dgspsp/bid-bmi/dsd-dsm/rvdi-divr/index.html>

Number of influenza surveillance regions† reporting widespread or localized influenza activity, Canada, by report week, 2003-2004 (N=52)

† 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, December 7 to December 13, 2003 (Week 50)
	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 the 2003-2004 season. 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.hc-sc.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, 2003-2004

Percent positive influenza tests, compared to other respiratory viruses by reporting week, Canada, 2003-2004

Influenza strain characterization, Canada, cumulative, 2003-2004 influenza season by the Respiratory Viruses Section at the National Microbiology Laboratory
[N=294]

NACI recommended components of the 2003-2004 Canadian vaccine include: an A/New Caledonia/20/99 (H1N1)–like virus, an A/Panama/2007/99 (H3N2)-like virus and either a B/Hong Kong/330/2001-like or B/Shangdong/7/97-like virus. Note: the influenza A(H1N2) virus strain is a reassortment virus derived from the influenza A (H1N1) and A(H3N2) virus strains. This strain circulated widely during the 2001-2002 season and like last season the current vaccine is expected to provide protection against this virus.
See http://www.hc-sc.gc.ca/pphb-dgspsp/publicat/ccdr-rmtc/03vol29/acs-dcc-4/index.html

Influenza-like illness (ILI) reporting rates, Canada, by report week, 2003-2004 compared to 1996/97 through 2002/2003 seasons

Note: No data available for mean rate in previous years for weeks 21 to 39 (1996-1997 through 2002-2003 seasons). During weeks 20-39, 2002-2003/ 2003-2004 seasons, ILI is reported once every two weeks, on even weeks only

Number of Outbreaks in Long Term Care Facilities by Report Week, Canada, 2003-2004