Canada:
Alberta reports both localized and sporadic activity. Ontario and British Columbia also report sporadic activity, while the rest of the country reports no activity (Manitoba and New Brunswick did not report this week) (see map). Across Canada, during the week ending May 15 (week 20), sentinel physicians reported seven cases of influenza-like illness (ILI) per 1000 patient visits, which is below the expected range for this time of year (see ILI graph). Health Canada received 1,103 reports of laboratory tests for influenza, including nine (0.8%) influenza A detections and zero influenza B detections (see table below). The National Microbiology Laboratory has antigenically characterized 825 influenza viruses to date, 793/825 (96.1%) were influenza A viruses, including 765/793 (96.5%) A/Fujian/411/02(H3N2)-like, 25 (3.2%) A/Panama/2007/99(H3N2)-like, two A/NewCaledonia/20/99(H1N1)-like and one H1N2. Thirty-two (32/825) were influenza B viruses, including seven B/Hong Kong/330/2001-like and 25 B/Sichuan/379/99-like. 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 737 outbreaks reported, including 453 influenza confirmed outbreaks in LTCF/retirement lodges (366) and hospitals (87), and 284 ILI outbreaks in schools (189) and other (95).

Avian Situation in BC: Highly pathogenic avian influenza has been identified on one new commercial poultry premises on May 5 and, as of May 18, the number of infected commercial premises is 41 in the Fraser Valley region. Positive premises have been depopulated and disinfection activities are underway. According to BC Health Authorities and Health Canada’s Workplace Health and Safety, no new confirmed human cases of H7 have been identified as of May 19th 2004.
CFIA update:

United States:
CDC: During the week ending May 8, 2004, New York reported regional activity. Five states reported sporadic activity while all other states reported no activity. ILI visits accounted for 0.8% of patient visits to sentinel physicians, which is below the national baseline of 2.5%. Sentinel cities reported 6.3% of deaths attributable to pneumonia and influenza, which is below the epidemic threshold of 7.7% for this week. A total of 904 influenza A(H3N2) isolates have been characterized to date; 106 (11.7%) were antigenically similar to the vaccine strain A/Panama/2007/99 and 798 (88.3%) were similar to the new drift variant A/Fujian/411/2002. CDC Weekly Report: http://www.cdc.gov/flu/weekly/

International:
SARS (WHO): WHO reports that the latest SARS outbreak in China is contained. Investigations continue at the National Institute of Virology in Beijing as the possible source of infection. WHO SARS Update:

Notice: FluWatch is now in its summer season of reporting. Surveillance activities such as sentinel physician reporting, laboratory reporting and provincial/territorial assignment of ILI activity levels will continue and Health Canada will publish FluWatch reports every two weeks (on even numbered weeks).

Total number of influenza tests performed and number of positive tWests 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 (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.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, May 9 to May 15, 2004 (Week 20)
	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.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, 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=825]

NACI recommended components of the 2003-2004 Canadian vaccine: A/New Caledonia/20/99 (H1N1)-like virus, A/Panama/2007/99 (H3N2)-like virus and either 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 H1N2 strain circulated widely during the 2001-2002 season and the current vaccine is expected to provide protection against this virus as well as providing good protection against A/Panama/2007/99(H3N2)-like viruses and some cross protection against the new A/Fujian/411/2002(H3N2)-like virus. However, the recently identified B/Sichuan/379/99-like viruses (B component of the 2001-2002 influenza vaccine) belong to a different lineage (B Yamagata lineage) than the B/Hong Kong/330/2001-like viruses included in this year's vaccine.

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

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

Definitions for the 2003-2004 season

[FluWatch]