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Canada:
Influenza activity remains low across the country, with reports of
sporadic activity in British Columbia, Alberta, Ontario, Quebec and Nova
Scotia (see map). Across Canada, during the
week ending March 27 (week 13), sentinel physicians reported 16 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 1,745 reports of
laboratory tests for influenza, including 24 (1.4%) influenza A detections
and 13 (0.75%)
influenza B detections (see table below). The National
Microbiology Laboratory has antigenically characterized 759 influenza viruses
to date, 744/759 (98.0%)
were influenza A viruses, including 717/744 (96.4%) A/Fujian/411/02(H3N2)-like,
25 (3.4%) A/Panama/2007/99(H3N2)-like, one A/NewCaledonia/20/99(H1N1)-like
and one H1N2. Fifteen (15/759) were influenza B viruses, including three
B/Hong Kong/330/2001-like and 12 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 730 outbreaks reported, including 447 influenza
confirmed outbreaks in LTCF/retirement lodges (360) and hospitals (87), and
283 ILI outbreaks in schools (188) and other (95).
Avian Situation in BC: As of March 31st 2004, CFIA has confirmed
avian influenza on seven commercial and three non-commercial poultry farms
in Fraser
Valley,
BC. Some individuals who had direct and prolonged exposure to affected poultry
or contaminated material have since reported mild symptoms, such as red eye,
headache, cough, runny nose or sore throat. Testing on samples taken from
two individuals confirmed influenza A (H7) infections. The symptoms for the
first exposed individual developed March 16 and fully resolved on March 21.
The second individual's symptoms developed March 25 and also resolved. Both
individuals were treated with the antiviral oseltamivir. At present, there
is no evidence of human-to-human transmission. Surveillance and follow up
continues for all exposed and all precautionary measures are being followed.
See CFIA update: <http://www.inspection.gc.ca/english/anima/heasan/disemala/avflu/avflue.shtml>
United States:
CDC: During the week ending March 20, 2004, most states reported sporadic
or no activity. ILI visits accounted for 1.2% of patient visits to sentinel
physicians, which is below the national baseline of 2.5%. Sentinel cities
reported 7.2% of deaths attributable to pneumonia and influenza, which is
below the epidemic threshold of 8.3% for this week. A total of 727 influenza
A(H3N2) isolates have been characterized to date; 106 (14.6%) were antigenically
similar to the vaccine strain A/Panama/2007/99 and 621 (85.4%) were similar
to the new drift variant A/Fujian/411/2002.
CDC: <http://www.cdc.gov/flu/weekly/>
International:
WHO and EISS: Influenza activity remains low around the
world.
Avian Influenza
(WHO): As of 2nd April 2004, no new human cases of H5N1 have been reported
since March 17th 2004 (see WHO
H5N1 update).
EISS: <http://www.eiss.org>
WHO
H5N1 Update: <http://www.who.int/csr/disease/avian_influenza/en/>
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Total number of influenza tests
performed and number of positive tests by province/territory of testing
laboratory, Canada, 2003-2004
Province
of
reporting
laboratories |
Report
Period:
March 21 to March 27, 2004 |
Season
to Date:
August 24, 2003 - March 27, 2004 |
Total #
Influenza
Tests |
# of
Positive Tests |
Total #
Influenza
Tests |
# of
Positive Tests |
| Influenza
A |
Influenza
B |
Total |
Influenza
A |
Influenza
B |
Total |
| NL |
4 |
0 |
0 |
0 |
917 |
152 |
0 |
152 |
| PE |
0 |
0 |
0 |
0 |
84 |
25 |
0 |
25 |
| NS |
0 |
0 |
0 |
0 |
1390 |
319 |
11 |
330 |
| NB |
17 |
1 |
0 |
1 |
1603 |
300 |
0 |
300 |
| QC |
534 |
21 |
6 |
27 |
16570 |
2715 |
54 |
2769 |
| ON |
583 |
0 |
6 |
6 |
29105 |
4465 |
31 |
4496 |
| MB |
61 |
0 |
0 |
0 |
2670 |
168 |
0 |
168 |
| SK |
134 |
1 |
0 |
1 |
5998 |
1070 |
1 |
1071 |
| AB |
342 |
0 |
1 |
1 |
13009 |
1187 |
1 |
1188 |
| BC |
70 |
1 |
0 |
1 |
3877 |
798 |
2 |
800 |
| Canada |
1745 |
24 |
13 |
37 |
75223 |
11199 |
100 |
11299 |
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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 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=759]
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
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