Re: Canada FluWatch Weekly Reports 2011-2012 Season Week 16
April 15 to April 21, 2012 (Week 16)
Posted 2012-04-27For readers interested in the <ABBR title="Portable Document Format">PDF</ABBR> version, the document is available for downloading or viewing:
<A title="Flu Watch (Version PDF, 159 KB - 7 pages)" href="http://www.phac-aspc.gc.ca/fluwatch/11-12/w16_12/pdf/fw2012-16-eng.pdf">2011-2012 FluWatch: April 15 to April 21, 2012 (Week 16) (<ABBR title="Portable Document Format">PDF</ABBR> Version - 159 <ABBR title=Kilobytes>KB</ABBR> - 7 pages)
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Overall Influenza Summary
<!-- END Menu container | FIN de conteneur du menu --><!-- ############################################# --><!-- CONTENT TITLE BEGINS | DEBUT DU TITRE DU CONTENU -->Influenza Activity (geographic spread) and Outbreaks
In week 16, 21 surveillance regions (within <ABBR title=Alberta>AB</ABBR>, <ABBR title=Saskatchewan>SK</ABBR>, <ABBR title=Manitoba>MB</ABBR>, <ABBR title=Ontario>ON</ABBR>, , <ABBR title="Nova Scotia">NS</ABBR>, <ABBR title="New Brunswick">NB</ABBR>, <ABBR title=Quebec>QC</ABBR> & <ABBR title="Newfoundland and Labrador">NL</ABBR>) reported localized activity and 28 regions (within all provinces and territories except in NL) reported sporadic influenza activity (see Figure 1). Thirty-one outbreaks of influenza or ILI were reported this week: 18 in long-term care facilities (3 in AB, 1 in SK, 2 in MB, 5 in ON, 5 in QC, 1 in NS & 1 in NL), 2 in schools (in NB) and 11 others (3 in AB, 5 in ON & 3 in NL) (Figure 3).
Figure 1. Map of overall Influenza activity level by province and territory,
Canada, Week 16
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 reported outbreaks. Please refer to detailed definitions on the last page. For areas where no data is reported, late reports from these provinces and territories will appear on the FluWatch website.
Text equivalent for figure 1Map of overall Influenza activity level by province and territory, Canada
Figure 2. Number of influenza surveillance regions<SUP title="sub-regions within the province or territory as defined by the provincial/territorial epidemiologist. Graph may change as late returns come in">?</SUP> reporting widespread or
localized influenza activity, Canada, by report week, 2011-2012 (N=56)
? sub-regions within the province or territory as defined by the provincial/territorial epidemiologist. Graph may change as late returns come in.
Text equivalent for figure 2Number of influenza surveillance regions reporting widespread or localized influenza activity, Canada, by report week, 2011-2012 (N=56)
Figure 3. Overall Number of Influenza Outbreaks, Canada, by Report Week, 2011-2012
Text equivalent for figure 3Overall Number of Influenza Outbreaks, Canada, by Report Week, 2011-2012
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Influenza and Other Respiratory Virus Detections
The proportion of positive influenza tests continued to decline this week and was 17.4% (731/4,211) (Figure 4 & 5). The proportion of positive detections for both influenza A (6.4%) and influenza B (11.0%) declined compared to the previous week. To date this season, influenza B remains the predominant virus type circulating in provinces east of Saskatchewan.
Cumulative to date of influenza virus detections by type/subtype is as follows: 48.6% influenza A (40.7% - A(H3); 18.8% - A(H1N1)pdm09; 40.5% - unsubtyped) and 51.4% influenza B (Table 1).
Detailed information on age and type/subtype were received on 8,627 cases to date this season (Table 2). The proportions of cases by age group are as follows: 21.2% were < 5 years; 18.0% were between 5-19 years; 22.4% were between 20-44 years; 15.3% were between 45-64 years of age; 22.9% were >= 65 years; and 0.2% with age unknown. The largest proportion of influenza A cases were between 20-44 years of age (26%) and those >=65 years of age (24%). The largest proportion of influenza B cases were under 20 years of age (47%).
In week 16, the percentage positive for other respiratory viruses remained similar to the previous week : RSV-7.4%; parainfluenza-1.3%; adenovirus-1.9%; hMPV-3.7%; rhinovirus-8.9 %; and coronavirus-3.1% (Figure 5). For more details, see the weekly Respiratory Virus Detections in Canada Report.
<TABLE class=widthFull border=1 cellSpacing=0 cellPadding=2><CAPTION class=alignCenter>Table 1: Weekly & Cumulative numbers of positive influenza specimens
by Provincial Laboratories, Canada, 2011-2012</CAPTION><THEAD><TR class=bg-colour-yellow><TH id=ar1 rowSpan=3>Reporting provinces</TH><TH id=ac1 colSpan=6>Weekly
(April 15 to April 21, 2012 ) </TH><TH id=ac9 colSpan=6>Cumulative
(August 28, 2011 to April 21, 2012 )</TH></TR><TR class=bg-colour-yellow><TH id=ac2 colSpan=5 headers=ac1>Influenza A</TH><TH id=ac8 headers=ac1>B</TH><TH id=ac10 colSpan=5 headers=ac9>Influenza A</TH><TH id=ac16 headers=ac9>B</TH></TR><TR class=bg-colour-yellow><TH id=ac3 headers="ac1 ac2">A Total</TH><TH id=ac4 headers="ac1 ac2">A(H1)</TH><TH id=ac5 headers="ac1 ac2">A(H3)</TH><TH id=ac6 headers="ac1 ac2">Pand H1N1</TH><TH id=ac7 class=noWrap headers="ac1 ac2">A
( <ABBR title=unsubtyped>Un S</ABBR>)*</TH><TH headers="ac1 ac8">Total</TH><TH id=ac11 headers="ac9 ac10">A Total</TH><TH id=ac12 headers="ac9 ac10">A(H1)</TH><TH id=ac13 headers="ac9 ac10">A(H3)</TH><TH id=ac14 headers="ac9 ac10">Pand H1N1</TH><TH id=ac15 class=noWrap headers="ac9 ac10">A
(Un S) *</TH><TH headers="ac9 ac16">Total</TH></TR></THEAD><TFOOT><TR><TD id=ar13 class=fontSize85 colSpan=13 headers=ar1>* Unsubtyped: The specimen was typed as influenza A, but no test for subtyping was performed. Specimens from <ABBR title=Nunavut>NT</ABBR>, <ABBR title=Yukon>YT</ABBR>, and <ABBR title=Nunavut>NU</ABBR> 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.</TD></TR></TFOOT><TBODY><TR><TH id=ar2 class=bg-colour-yellow headers=ar1><ABBR title="British Columbia ">BC</ABBR></TH><TD class=alignCenter headers="ar1 ar2 ac1 ac2 ac3">28 </TD><TD class=alignCenter headers="ar1 ar2 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar2 ac1 ac2 ac5">18 </TD><TD class=alignCenter headers="ar1 ar2 ac1 ac2 ac6">9 </TD><TD class=alignCenter headers="ar1 ar2 ac1 ac2 ac7">1 </TD><TD class=alignCenter headers="ar1 ar2 ac1 ac8">5 </TD><TD class=alignCenter headers="ar1 ar2 ac9 ac10 ac11">532 </TD><TD class=alignCenter headers="ar1 ar2 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar2 ac9 ac10 ac13">429 </TD><TD class=alignCenter headers="ar1 ar2 ac9 ac10 ac14">90 </TD><TD class=alignCenter headers="ar1 ar2 ac9 ac10 ac15">13 </TD><TD class=alignCenter headers="ar1 ar2 ac9 ac16">90 </TD></TR><TR><TH id=ar3 class=bg-colour-yellow headers=ar1><ABBR title=Alberta>AB</ABBR></TH><TD class=alignCenter headers="ar1 ar3 ac1 ac2 ac3">92 </TD><TD class=alignCenter headers="ar1 ar3 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar3 ac1 ac2 ac5">63 </TD><TD class=alignCenter headers="ar1 ar3 ac1 ac2 ac6">12 </TD><TD class=alignCenter headers="ar1 ar3 ac1 ac2 ac7">17 </TD><TD class=alignCenter headers="ar1 ar3 ac1 ac8">22 </TD><TD class=alignCenter headers="ar1 ar3 ac9 ac10 ac11">1191 </TD><TD class=alignCenter headers="ar1 ar3 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar3 ac9 ac10 ac13">943 </TD><TD class=alignCenter headers="ar1 ar3 ac9 ac10 ac14">191 </TD><TD class=alignCenter headers="ar1 ar3 ac9 ac10 ac15">57 </TD><TD class=alignCenter headers="ar1 ar3 ac9 ac16">164 </TD></TR><TR><TH id=ar4 class=bg-colour-yellow headers=ar1><ABBR title=Saskatchewan>SK</ABBR></TH><TD class=alignCenter headers="ar1 ar4 ac1 ac2 ac3">17 </TD><TD class=alignCenter headers="ar1 ar4 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar4 ac1 ac2 ac5">8 </TD><TD class=alignCenter headers="ar1 ar4 ac1 ac2 ac6">2 </TD><TD class=alignCenter headers="ar1 ar4 ac1 ac2 ac7">7 </TD><TD class=alignCenter headers="ar1 ar4 ac1 ac8">9 </TD><TD class=alignCenter headers="ar1 ar4 ac9 ac10 ac11">494 </TD><TD class=alignCenter headers="ar1 ar4 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar4 ac9 ac10 ac13">311 </TD><TD class=alignCenter headers="ar1 ar4 ac9 ac10 ac14">47 </TD><TD class=alignCenter headers="ar1 ar4 ac9 ac10 ac15">136 </TD><TD class=alignCenter headers="ar1 ar4 ac9 ac16">62 </TD></TR><TR><TH id=ar5 class=bg-colour-yellow headers=ar1><ABBR title=Manitoba>MB</ABBR></TH><TD class=alignCenter headers="ar1 ar5 ac1 ac2 ac3">4 </TD><TD class=alignCenter headers="ar1 ar5 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar5 ac1 ac2 ac5">0 </TD><TD class=alignCenter headers="ar1 ar5 ac1 ac2 ac6">4 </TD><TD class=alignCenter headers="ar1 ar5 ac1 ac2 ac7">0 </TD><TD class=alignCenter headers="ar1 ar5 ac1 ac8">7 </TD><TD class=alignCenter headers="ar1 ar5 ac9 ac10 ac11">68 </TD><TD class=alignCenter headers="ar1 ar5 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar5 ac9 ac10 ac13">8 </TD><TD class=alignCenter headers="ar1 ar5 ac9 ac10 ac14">7 </TD><TD class=alignCenter headers="ar1 ar5 ac9 ac10 ac15">53 </TD><TD class=alignCenter headers="ar1 ar5 ac9 ac16">192 </TD></TR><TR><TH id=ar6 class=bg-colour-yellow headers=ar1><ABBR title=Ontario>ON</ABBR></TH><TD class=alignCenter headers="ar1 ar6 ac1 ac2 ac3">25 </TD><TD class=alignCenter headers="ar1 ar6 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar6 ac1 ac2 ac5">5 </TD><TD class=alignCenter headers="ar1 ar6 ac1 ac2 ac6">10 </TD><TD class=alignCenter headers="ar1 ar6 ac1 ac2 ac7">10 </TD><TD class=alignCenter headers="ar1 ar6 ac1 ac8">158 </TD><TD class=alignCenter headers="ar1 ar6 ac9 ac10 ac11">870 </TD><TD class=alignCenter headers="ar1 ar6 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar6 ac9 ac10 ac13">218 </TD><TD class=alignCenter headers="ar1 ar6 ac9 ac10 ac14">470 </TD><TD class=alignCenter headers="ar1 ar6 ac9 ac10 ac15">182 </TD><TD class=alignCenter headers="ar1 ar6 ac9 ac16">2356 </TD></TR><TR><TH id=ar7 class=bg-colour-yellow headers=ar1><ABBR title=Quebec>QC</ABBR>
</TH><TD class=alignCenter headers="ar1 ar7 ac1 ac2 ac3">82 </TD><TD class=alignCenter headers="ar1 ar7 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar7 ac1 ac2 ac5">7 </TD><TD class=alignCenter headers="ar1 ar7 ac1 ac2 ac6">0 </TD><TD class=alignCenter headers="ar1 ar7 ac1 ac2 ac7">75 </TD><TD class=alignCenter headers="ar1 ar7 ac1 ac8">190 </TD><TD class=alignCenter headers="ar1 ar7 ac9 ac10 ac11">1670 </TD><TD class=alignCenter headers="ar1 ar7 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar7 ac9 ac10 ac13">56 </TD><TD class=alignCenter headers="ar1 ar7 ac9 ac10 ac14">92 </TD><TD class=alignCenter headers="ar1 ar7 ac9 ac10 ac15">1522 </TD><TD class=alignCenter headers="ar1 ar7 ac9 ac16">1837 </TD></TR><TR><TH id=ar8 class=bg-colour-yellow headers=ar1><ABBR title="New Brunswick">NB</ABBR>
</TH><TD class=alignCenter headers="ar1 ar8 ac1 ac2 ac3">6 </TD><TD class=alignCenter headers="ar1 ar8 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar8 ac1 ac2 ac5">0 </TD><TD class=alignCenter headers="ar1 ar8 ac1 ac2 ac6">5 </TD><TD class=alignCenter headers="ar1 ar8 ac1 ac2 ac7">1 </TD><TD class=alignCenter headers="ar1 ar8 ac1 ac8">57 </TD><TD class=alignCenter headers="ar1 ar8 ac9 ac10 ac11">62 </TD><TD class=alignCenter headers="ar1 ar8 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar8 ac9 ac10 ac13">17 </TD><TD class=alignCenter headers="ar1 ar8 ac9 ac10 ac14">26 </TD><TD class=alignCenter headers="ar1 ar8 ac9 ac10 ac15">19 </TD><TD class=alignCenter headers="ar1 ar8 ac9 ac16">240 </TD></TR><TR><TH id=ar9 class=bg-colour-yellow headers=ar1><ABBR title="Nova Scotia ">NS</ABBR>
</TH><TD class=alignCenter headers="ar1 ar9 ac1 ac2 ac3">3 </TD><TD class=alignCenter headers="ar1 ar9 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar9 ac1 ac2 ac5">2 </TD><TD class=alignCenter headers="ar1 ar9 ac1 ac2 ac6">0 </TD><TD class=alignCenter headers="ar1 ar9 ac1 ac2 ac7">1 </TD><TD class=alignCenter headers="ar1 ar9 ac1 ac8">4 </TD><TD class=alignCenter headers="ar1 ar9 ac9 ac10 ac11">14 </TD><TD class=alignCenter headers="ar1 ar9 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar9 ac9 ac10 ac13">9 </TD><TD class=alignCenter headers="ar1 ar9 ac9 ac10 ac14">1 </TD><TD class=alignCenter headers="ar1 ar9 ac9 ac10 ac15">4 </TD><TD class=alignCenter headers="ar1 ar9 ac9 ac16">88 </TD></TR><TR><TH id=ar10 class=bg-colour-yellow headers=ar1><ABBR title="Prince Edward Island ">PE</ABBR>
</TH><TD class=alignCenter headers="ar1 ar10 ac1 ac2 ac3">0 </TD><TD class=alignCenter headers="ar1 ar10 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar10 ac1 ac2 ac5">0 </TD><TD class=alignCenter headers="ar1 ar10 ac1 ac2 ac6">0 </TD><TD class=alignCenter headers="ar1 ar10 ac1 ac2 ac7">0 </TD><TD class=alignCenter headers="ar1 ar10 ac1 ac8">7 </TD><TD class=alignCenter headers="ar1 ar10 ac9 ac10 ac11">3 </TD><TD class=alignCenter headers="ar1 ar10 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar10 ac9 ac10 ac13">2 </TD><TD class=alignCenter headers="ar1 ar10 ac9 ac10 ac14">1 </TD><TD class=alignCenter headers="ar1 ar10 ac9 ac10 ac15">0 </TD><TD class=alignCenter headers="ar1 ar10 ac9 ac16">38 </TD></TR><TR><TH id=ar11 class=bg-colour-yellow headers=ar1><ABBR title="Newfoundland/Labrador ">NL</ABBR>
</TH><TD class=alignCenter headers="ar1 ar11 ac1 ac2 ac3">12 </TD><TD class=alignCenter headers="ar1 ar11 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar11 ac1 ac2 ac5">0 </TD><TD class=alignCenter headers="ar1 ar11 ac1 ac2 ac6">1 </TD><TD class=alignCenter headers="ar1 ar11 ac1 ac2 ac7">11 </TD><TD class=alignCenter headers="ar1 ar11 ac1 ac8">3 </TD><TD class=alignCenter headers="ar1 ar11 ac9 ac10 ac11">71 </TD><TD class=alignCenter headers="ar1 ar11 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar11 ac9 ac10 ac13">30 </TD><TD class=alignCenter headers="ar1 ar11 ac9 ac10 ac14">10 </TD><TD class=alignCenter headers="ar1 ar11 ac9 ac10 ac15">31 </TD><TD class=alignCenter headers="ar1 ar11 ac9 ac16">198 </TD></TR><TR><TH id=ar12 class=bg-colour-yellow headers=ar1>Canada</TH><TD class=alignCenter headers="ar1 ar12 ac1 ac2 ac3">269 </TD><TD class=alignCenter headers="ar1 ar12 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar12 ac1 ac2 ac5">103 </TD><TD class=alignCenter headers="ar1 ar12 ac1 ac2 ac6">43 </TD><TD class=alignCenter headers="ar1 ar12 ac1 ac2 ac7">123 </TD><TD class=alignCenter headers="ar1 ar12 ac1 ac8">462 </TD><TD class=alignCenter headers="ar1 ar12 ac9 ac10 ac11">4975 </TD><TD class=alignCenter headers="ar1 ar12 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar12 ac9 ac10 ac13">2023 </TD><TD class=alignCenter headers="ar1 ar12 ac9 ac10 ac14">935 </TD><TD class=alignCenter headers="ar1 ar12 ac9 ac10 ac15">2017 </TD><TD class=alignCenter headers="ar1 ar12 ac9 ac16">5265 </TD></TR></TBODY></TABLE>
<TABLE class=widthFull border=1 cellSpacing=0 cellPadding=2><CAPTION>Table 2. Weekly & Cumulative numbers of positive influenza specimens by age groups
reported through case-based laboratory reporting, Canada, 2011-2012 *</CAPTION><THEAD><TR class=bg-colour-yellow><TH id=br1 rowSpan=3>Age groups</TH><TH id=bc1 colSpan=5>Weekly
April 15 to April 21, 2012 </TH><TH id=bc8 colSpan=5>Cumulative
(Aug. 28, 2011 to April 21, 2012 )</TH></TR><TR class=bg-colour-yellow><TH id=bc2 colSpan=4 headers=bc1>Influenza A</TH><TH id=bc7 headers=bc1>B</TH><TH id=bc9 colSpan=4 headers=bc8>Influenza A</TH><TH id=bc14 headers=bc8>B</TH></TR><TR class=bg-colour-yellow><TH id=bc3 headers="bc1 bc2">A Total</TH><TH id=bc4 headers="bc1 bc2">Pandemic H1N1</TH><TH id=bc5 headers="bc1 bc2">A/H3N2</TH><TH id=bc6 headers="bc1 bc2">A unsubtyped</TH><TH headers="bc1 bc7">Total</TH><TH id=bc10 headers="bc8 bc9">A Total</TH><TH id=bc11 headers="bc8 bc9">Pandemic H1N1</TH><TH id=bc12 headers="bc8 bc9">A/H3N2</TH><TH id=bc13 headers="bc8 bc9">A unsubtyped</TH><TH headers="bc8 bc14">Total</TH></TR></THEAD><TFOOT><TR><TD id=br9 class=fontSize85 colSpan=11 headers=br1>* Please note that this table reflects the number of specimens for which demographic information was reported.
These represent a subset of all positive influenza cases reported. Delays in the reporting of data may cause data to change retrospectively.</TD></TR></TFOOT><TBODY><TR><TH id=br2 headers=br1>< 5</TH><TD class=alignCenter headers="br1 br2 bc1 bc2 bc3">31 </TD><TD class=alignCenter headers="br1 br2 bc1 bc2 bc4">5 </TD><TD class=alignCenter headers="br1 br2 bc1 bc2 bc5">10 </TD><TD class=alignCenter headers="br1 br2 bc1 bc2 bc6">16 </TD><TD class=alignCenter headers="br1 br2 bc1 bc7">46 </TD><TD class=alignCenter headers="br1 br2 bc8 bc9 bc10">894 </TD><TD class=alignCenter headers="br1 br2 bc8 bc9 bc11">193 </TD><TD class=alignCenter headers="br1 br2 bc8 bc9 bc12">318 </TD><TD class=alignCenter headers="br1 br2 bc8 bc9 bc13">383 </TD><TD class=alignCenter headers="br1 br2 bc8 bc14">934 </TD></TR><TR><TH id=br3 headers=br1>5-19</TH><TD class=alignCenter headers="br1 br3 bc1 bc2 bc3">16 </TD><TD class=alignCenter headers="br1 br3 bc1 bc2 bc4">0 </TD><TD class=alignCenter headers="br1 br3 bc1 bc2 bc5">5 </TD><TD class=alignCenter headers="br1 br3 bc1 bc2 bc6">11 </TD><TD class=alignCenter headers="br1 br3 bc1 bc7">38 </TD><TD class=alignCenter headers="br1 br3 bc8 bc9 bc10">518 </TD><TD class=alignCenter headers="br1 br3 bc8 bc9 bc11">74 </TD><TD class=alignCenter headers="br1 br3 bc8 bc9 bc12">261 </TD><TD class=alignCenter headers="br1 br3 bc8 bc9 bc13">183 </TD><TD class=alignCenter headers="br1 br3 bc8 bc14">1032 </TD></TR><TR><TH id=br4 headers=br1>20-44</TH><TD class=alignCenter headers="br1 br4 bc1 bc2 bc3">24 </TD><TD class=alignCenter headers="br1 br4 bc1 bc2 bc4">5 </TD><TD class=alignCenter headers="br1 br4 bc1 bc2 bc5">8 </TD><TD class=alignCenter headers="br1 br4 bc1 bc2 bc6">11 </TD><TD class=alignCenter headers="br1 br4 bc1 bc7">44 </TD><TD class=alignCenter headers="br1 br4 bc8 bc9 bc10">1170 </TD><TD class=alignCenter headers="br1 br4 bc8 bc9 bc11">253 </TD><TD class=alignCenter headers="br1 br4 bc8 bc9 bc12">430 </TD><TD class=alignCenter headers="br1 br4 bc8 bc9 bc13">487 </TD><TD class=alignCenter headers="br1 br4 bc8 bc14">765 </TD></TR><TR><TH id=br5 headers=br1>45-64</TH><TD class=alignCenter headers="br1 br5 bc1 bc2 bc3">26 </TD><TD class=alignCenter headers="br1 br5 bc1 bc2 bc4">6 </TD><TD class=alignCenter headers="br1 br5 bc1 bc2 bc5">7 </TD><TD class=alignCenter headers="br1 br5 bc1 bc2 bc6">13 </TD><TD class=alignCenter headers="br1 br5 bc1 bc7">40 </TD><TD class=alignCenter headers="br1 br5 bc8 bc9 bc10">792 </TD><TD class=alignCenter headers="br1 br5 bc8 bc9 bc11">164 </TD><TD class=alignCenter headers="br1 br5 bc8 bc9 bc12">268 </TD><TD class=alignCenter headers="br1 br5 bc8 bc9 bc13">360 </TD><TD class=alignCenter headers="br1 br5 bc8 bc14">529 </TD></TR><TR><TH id=br6 headers=br1>65+</TH><TD class=alignCenter headers="br1 br6 bc1 bc2 bc3">67 </TD><TD class=alignCenter headers="br1 br6 bc1 bc2 bc4">0 </TD><TD class=alignCenter headers="br1 br6 bc1 bc2 bc5">30 </TD><TD class=alignCenter headers="br1 br6 bc1 bc2 bc6">37 </TD><TD class=alignCenter headers="br1 br6 bc1 bc7">85 </TD><TD class=alignCenter headers="br1 br6 bc8 bc9 bc10">1076 </TD><TD class=alignCenter headers="br1 br6 bc8 bc9 bc11">64 </TD><TD class=alignCenter headers="br1 br6 bc8 bc9 bc12">659 </TD><TD class=alignCenter headers="br1 br6 bc8 bc9 bc13">353 </TD><TD class=alignCenter headers="br1 br6 bc8 bc14">896 </TD></TR><TR><TH id=br7 headers=br1>Unknown</TH><TD class=alignCenter headers="br1 br7 bc1 bc2 bc3">0 </TD><TD class=alignCenter headers="br1 br7 bc1 bc2 bc4">0 </TD><TD class=alignCenter headers="br1 br7 bc1 bc2 bc5">0 </TD><TD class=alignCenter headers="br1 br7 bc1 bc2 bc6">0 </TD><TD class=alignCenter headers="br1 br7 bc1 bc7">0 </TD><TD class=alignCenter headers="br1 br7 bc8 bc9 bc10">18 </TD><TD class=alignCenter headers="br1 br7 bc8 bc9 bc11">6 </TD><TD class=alignCenter headers="br1 br7 bc8 bc9 bc12">11 </TD><TD class=alignCenter headers="br1 br7 bc8 bc9 bc13">1 </TD><TD class=alignCenter headers="br1 br7 bc8 bc14">3 </TD></TR><TR><TH id=br8 headers=br1>Total</TH><TD class=alignCenter headers="br1 br8 bc1 bc2 bc3">164 </TD><TD class=alignCenter headers="br1 br8 bc1 bc2 bc4">16 </TD><TD class=alignCenter headers="br1 br8 bc1 bc2 bc5">60 </TD><TD class=alignCenter headers="br1 br8 bc1 bc2 bc6">88 </TD><TD class=alignCenter headers="br1 br8 bc1 bc7">253 </TD><TD class=alignCenter headers="br1 br8 bc8 bc9 bc10">4468 </TD><TD class=alignCenter headers="br1 br8 bc8 bc9 bc11">754 </TD><TD class=alignCenter headers="br1 br8 bc8 bc9 bc12">1947 </TD><TD class=alignCenter headers="br1 br8 bc8 bc9 bc13">1767 </TD><TD class=alignCenter headers="br1 br8 bc8 bc14">4159 </TD></TR></TBODY></TABLE>
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Figure 4. Influenza tests reported and percentage of tests positive, Canada,
by report week, 2011-2012
Text equivalent for figure 4Influenza tests reported and percentage of tests positive, Canada, by report week, 2011-2012
Figure 5. Percent positive influenza tests, compared to other respiratory viruses,
Canada, by reporting week, 2011-2012
Text equivalent for figure 5Percent positive influenza tests, compared to other respiratory viruses, Canada, by reporting week, 2011-2012
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Influenza strain characterizations
Since the start of the season, the National Microbiology Laboratory (<ABBR title="National Microbiology Laboratory">NML</ABBR>) has antigenically characterized 969 influenza viruses (189 A/H3N2, 178 A/H1N1 and 602 B). Of the 189 A/H3N2 viruses (from BC, AB, SK, MB, ON, QC, NS & NT), 170 (90.0%) were antigenically similar to A/Perth/16/2009 while 19 (10.0%) viruses showed reduced titers with antiserum produced against A/Perth/16/2009. Of the 178 A/H1N1 viruses characterized (from BC, AB, SK, MB, ON, QC & NB), 173 (97.2%) were antigenically similar to A/California/07/2009 and 5 (2.8%) viruses tested showed reduced titer with antiserum produced against A/California/07/2009. Of the 602 influenza B viruses characterized, 306 (50.8%) (from BC, AB, SK, MB, ON, QC, NB, NS & NL) were antigenically similar to the vaccine strain B/Brisbane/60/2008 (Victoria lineage); however 1 virus out of the 306 tested showed reduced titer with antiserum produced against B/Brisbane/60/2008. The remaining 296 (49.2%) influenza B viruses (from BC, AB, MB, ON, QC, NB, NS & NU) are antigenically related to the reference virus B/Wisconsin/01/2010-like, which belongs to the Yamagata lineage. (Figure 6)
Figure 6. Influenza strain characterizations, Canada, 2011-2012, N = 969
Note: The recommended components for the 2011-2012 Northern Hemisphere influenza vaccine include: A/Perth/16/2009 (H3N2), A/California/7/2009 (H1N1) and B/Brisbane/60/2008.
Text equivalent for figure 6Influenza strain characterizations, Canada, 2011-2012
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Antiviral resistance
Since the beginning of the season, NML has tested 937 influenza viruses for resistance to oseltamivir (by phenotypic assay and/or sequencing) and 936 for zanamivir (by phenotypic assay) and it was found that all viruses tested were susceptible to oseltamivir and zanamivir. A total of 558 influenza A viruses (309 H3N2 and 249 H1N1) were tested for amantadine resistance; all but 1 influenza A(H3N2) virus tested were resistant. (Table 3)
<TABLE class=widthFull border=1 cellSpacing=0 cellPadding=2><CAPTION>Table 3. Antiviral resistance by influenza virus type and subtype, Canada, 2011-2012 </CAPTION><THEAD><TR class=bg-colour-yellow><TH id=cr1 rowSpan=2>Virus type and subtype</TH><TH id=cc1 colSpan=2>Oseltamivir</TH><TH id=cc4 colSpan=2>Zanamivir</TH><TH id=cc7 colSpan=2>Amantadine</TH></TR><TR class=bg-colour-yellow><TH id=cc2 headers=cc1># tested</TH><TH id=cc3 headers=cc1># resistant (%)</TH><TH id=cc5 headers=cc4># tested</TH><TH id=cc6 headers=cc4># resistant (%)</TH><TH id=cc8 headers=cc7># tested</TH><TH id=cc9 headers=cc7># resistant (%)</TH></TR></THEAD><TFOOT><TR><TD id=cr6 class=fontSize85 colSpan=7 headers=cr1><SUP>*</SUP> NA - not applicable</TD></TR></TFOOT><TBODY><TR><TH id=cr2 class="alignLeft bg-colour-blue" headers=cr1>A (H3N2)</TH><TD class=alignCenter headers="cr1 cr2 cc1 cc2">182 </TD><TD class=alignCenter headers="cr1 cr2 cc1 cc3">0 </TD><TD class=alignCenter headers="cr1 cr2 cc4 cc5">183 </TD><TD class=alignCenter headers="cr1 cr2 cc4 cc6">0 </TD><TD class=alignCenter headers="cr1 cr2 cc7 cc8">309 </TD><TD class=alignCenter headers="cr1 cr2 cc7 cc9">308 (99.7%) </TD></TR><TR><TH id=cr3 class="alignLeft bg-colour-blue" headers=cr1>A (H1N1)</TH><TD class=alignCenter headers="cr1 cr3 cc1 cc2">190 </TD><TD class=alignCenter headers="cr1 cr3 cc1 cc3">0 </TD><TD class=alignCenter headers="cr1 cr3 cc4 cc5">190 </TD><TD class=alignCenter headers="cr1 cr3 cc4 cc6">0 </TD><TD class=alignCenter headers="cr1 cr3 cc7 cc8">249 </TD><TD class=alignCenter headers="cr1 cr3 cc7 cc9">249 (100%) </TD></TR><TR><TH id=cr4 class="alignLeft bg-colour-blue" headers=cr1>B</TH><TD class=alignCenter headers="cr1 cr4 cc1 cc2">565 </TD><TD class=alignCenter headers="cr1 cr4 cc1 cc3">0 </TD><TD class=alignCenter headers="cr1 cr4 cc4 cc5">565 </TD><TD class=alignCenter headers="cr1 cr4 cc4 cc6">0 </TD><TD class=alignCenter headers="cr1 cr4 cc7 cc8">NA* </TD><TD class=alignCenter headers="cr1 cr4 cc7 cc9">NA* </TD></TR><TR><TH id=cr5 class="alignLeft bg-colour-blue" headers=cr1>TOTAL</TH><TD class=alignCenter headers="cr1 cr5 cc1 cc2">937 </TD><TD class=alignCenter headers="cr1 cr5 cc1 cc3">0 </TD><TD class=alignCenter headers="cr1 cr5 cc4 cc5">938 </TD><TD class=alignCenter headers="cr1 cr5 cc4 cc6">0 </TD><TD class=alignCenter headers="cr1 cr5 cc7 cc8">558 </TD><TD class=alignCenter headers="cr1 cr5 cc7 cc9">557 (99.8%) </TD></TR></TBODY></TABLE>
Influenza-like Illness (ILI) Consultation Rate
The national ILI consultation rate declined from the previous week (17.5 ILI consultations per 1,000 patient visits in week 16) but remains within the expected levels for this time of year (Figure 7). The highest consultation rates this week were observed children under 5 (41.4/1,000 visits) and in those between 5 to 19 years old (19.2/1,000 visits).
Figure 7. Influenza-like illness (ILI) consultation rates, Canada, by report week, 2011-2012 compared to 1996/97 through to 2010/11 seasons (with pandemic data suppressed)
Note: No data available for mean rate in previous years for weeks 19 to 39 (1996-1997 through 2002-2003 seasons). Delays in the reporting of data may cause data to change retrospectively.
Text equivalent for figure 7Influenza-like illness (ILI) consultation rates, Canada, by report week, 2011-2012 compared to 1996/97 through to 2010/11 seasons (with pandemic data suppressed)
Severe Respiratory Illness Surveillance
Paediatric Influenza Hospitalizations and Deaths (IMPACT)
In week 16, 18 new laboratory-confirmed influenza-associated paediatric (16 years of age and under) hospitalizations were reported through the Immunization Monitoring Program Active (IMPACT) network. Four hospitalizations were due to influenza A (unsubtyped) (in BC & QC); 1 was due to A(H3N2) (in AB), 1 was due to A(H1N1) (in AB) and 12 were due to influenza B (in AB, ON, QC & NS).
To date this season, 502 influenza-associated paediatric hospitalizations have been reported through IMPACT (from BC, AB, SK, MB, ON, QC, NS & NL); 223 (44.4%) were due to influenza A and 279 (55.6%) were due to influenza B. The proportion of cases by age group is as follows: 15.1% among infants <6 months of age; 20.9% among children 6-23 months of age; 31.5% were between 2-4 years; 22.1% were between 5-9 years; and 10.4% were between 10-16 years. To date this season, 4 influenza B associated deaths have been reported through the IMPACT network.
Note: The number of hospitalizations reported through IMPACT represents a subset of all influenza-associate paediatric hospitalizations in Canada; therefore, the number of hospitalizations included in this report may differ from those reported by other Provincial and Territorial Health Authorities.
Influenza Hospitalizations and Deaths (Aggregate Surveillance System)
In week 16, 123 new laboratory-confirmed influenza-associated hospitalizations were reported of which 35 (28.5%) were in those < 20 years of age and 88 (71.5%) in those ≥ 20 years of age; 24.4% due to influenza A and 75.6% due to influenza B. The hospitalizations were reported in AB (10), MB (5), ON (103), PE (1) and NL (4). Of the 123 hospitalizations, 1 required admission to ICU (MB) and was associated with influenza A(H1N1)pmd09 infection. In addition, there were 5 adult influenza-associated deaths reported (in ON); all 5 deaths were associated with influenza B infection and all cases were ≥ 65 years of age.
To date this season, 1,354 influenza-associated hospitalizations have been reported from 7 provinces (AB, SK, MB, ON, NS, PE & NL) and 2 territories (YT & NT). The largest proportion of cases was observed in those > 65 years of age (32.3%). Influenza B (55.6%) continues to be the predominant influenza type among hospitalized cases compared to influenza A (44.4%); of those influenza A hospitalizations where subtype was available, influenza A(H3N2) predominated (57.9%). There have been 55 hospitalizations requiring ICU admission reported (from AB, SK, MB, NS & NL) of which 29.1% were < 20 years of age and 70.9% were ≥ 20 years of age. To date this season, 76 influenza-associated deaths have been reported (from AB, SK, MB, ON & NS) of which 6.6% were among those < 20 years of age and 93.4% in those ≥ 20 years of age. Of the adult deaths, 78.9% were in those ≥ 65 years of age.
Note: Some of the hospitalizations and deaths reported in those < 16 years of age may also have been reported in the IMPACT summary above if the hospitalization or death occurred in one of the 12 IMPACT hospitals. The reason for hospitalization or cause of death does not have to be attributable to influenza in order to be reported. Influenza-associated hospitalizations are not reported to PHAC by the following Provinces: BC, & QC. Only hospitalizations that require intensive medical care are reported by SK. ICU admissions are not reported in ON.
.../
April 15 to April 21, 2012 (Week 16)
Posted 2012-04-27For readers interested in the <ABBR title="Portable Document Format">PDF</ABBR> version, the document is available for downloading or viewing:
<A title="Flu Watch (Version PDF, 159 KB - 7 pages)" href="http://www.phac-aspc.gc.ca/fluwatch/11-12/w16_12/pdf/fw2012-16-eng.pdf">2011-2012 FluWatch: April 15 to April 21, 2012 (Week 16) (<ABBR title="Portable Document Format">PDF</ABBR> Version - 159 <ABBR title=Kilobytes>KB</ABBR> - 7 pages)
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Overall Influenza Summary
- Although the peak of activity for the 2011-2012 influenza season in Canada has passed, several regions are still reporting elevated influenza activity (i.e. in the Atlantic Region, Quebec, Ontario, and the Prairies).
- Thirty-one outbreaks of influenza or <ABBR title="Influenza-like illness">ILI</ABBR> were reported this week (18 in LTCFs, 2 in schools and 11 others).
- In week 16, 731 laboratory detections of influenza were reported (14.1% - A(H3); 5.9% - A(H1N1)pdm09; 16.8% - unsubtyped and 63.2% influenza B). To date this season, influenza B remains the predominant virus type circulating in provinces east of Saskatchewan.
- 106 influenza-associated hospitalizations were reported this week (18 paediatric through <ABBR title="Immunization Monitoring Program Active">IMPACT</ABBR> surveillance and 88 adult through aggregate surveillance)
- The ILI consultation rate declined compared to the previous week but remains within expected levels.
<!-- END Menu container | FIN de conteneur du menu --><!-- ############################################# --><!-- CONTENT TITLE BEGINS | DEBUT DU TITRE DU CONTENU -->Influenza Activity (geographic spread) and Outbreaks
In week 16, 21 surveillance regions (within <ABBR title=Alberta>AB</ABBR>, <ABBR title=Saskatchewan>SK</ABBR>, <ABBR title=Manitoba>MB</ABBR>, <ABBR title=Ontario>ON</ABBR>, , <ABBR title="Nova Scotia">NS</ABBR>, <ABBR title="New Brunswick">NB</ABBR>, <ABBR title=Quebec>QC</ABBR> & <ABBR title="Newfoundland and Labrador">NL</ABBR>) reported localized activity and 28 regions (within all provinces and territories except in NL) reported sporadic influenza activity (see Figure 1). Thirty-one outbreaks of influenza or ILI were reported this week: 18 in long-term care facilities (3 in AB, 1 in SK, 2 in MB, 5 in ON, 5 in QC, 1 in NS & 1 in NL), 2 in schools (in NB) and 11 others (3 in AB, 5 in ON & 3 in NL) (Figure 3).
Figure 1. Map of overall Influenza activity level by province and territory,
Canada, Week 16
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 reported outbreaks. Please refer to detailed definitions on the last page. For areas where no data is reported, late reports from these provinces and territories will appear on the FluWatch website.
Text equivalent for figure 1Map of overall Influenza activity level by province and territory, Canada
Figure 2. Number of influenza surveillance regions<SUP title="sub-regions within the province or territory as defined by the provincial/territorial epidemiologist. Graph may change as late returns come in">?</SUP> reporting widespread or
localized influenza activity, Canada, by report week, 2011-2012 (N=56)
? sub-regions within the province or territory as defined by the provincial/territorial epidemiologist. Graph may change as late returns come in.
Text equivalent for figure 2Number of influenza surveillance regions reporting widespread or localized influenza activity, Canada, by report week, 2011-2012 (N=56)
Figure 3. Overall Number of Influenza Outbreaks, Canada, by Report Week, 2011-2012
Text equivalent for figure 3Overall Number of Influenza Outbreaks, Canada, by Report Week, 2011-2012
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Influenza and Other Respiratory Virus Detections
The proportion of positive influenza tests continued to decline this week and was 17.4% (731/4,211) (Figure 4 & 5). The proportion of positive detections for both influenza A (6.4%) and influenza B (11.0%) declined compared to the previous week. To date this season, influenza B remains the predominant virus type circulating in provinces east of Saskatchewan.
Cumulative to date of influenza virus detections by type/subtype is as follows: 48.6% influenza A (40.7% - A(H3); 18.8% - A(H1N1)pdm09; 40.5% - unsubtyped) and 51.4% influenza B (Table 1).
Detailed information on age and type/subtype were received on 8,627 cases to date this season (Table 2). The proportions of cases by age group are as follows: 21.2% were < 5 years; 18.0% were between 5-19 years; 22.4% were between 20-44 years; 15.3% were between 45-64 years of age; 22.9% were >= 65 years; and 0.2% with age unknown. The largest proportion of influenza A cases were between 20-44 years of age (26%) and those >=65 years of age (24%). The largest proportion of influenza B cases were under 20 years of age (47%).
In week 16, the percentage positive for other respiratory viruses remained similar to the previous week : RSV-7.4%; parainfluenza-1.3%; adenovirus-1.9%; hMPV-3.7%; rhinovirus-8.9 %; and coronavirus-3.1% (Figure 5). For more details, see the weekly Respiratory Virus Detections in Canada Report.
<TABLE class=widthFull border=1 cellSpacing=0 cellPadding=2><CAPTION class=alignCenter>Table 1: Weekly & Cumulative numbers of positive influenza specimens
by Provincial Laboratories, Canada, 2011-2012</CAPTION><THEAD><TR class=bg-colour-yellow><TH id=ar1 rowSpan=3>Reporting provinces</TH><TH id=ac1 colSpan=6>Weekly
(April 15 to April 21, 2012 ) </TH><TH id=ac9 colSpan=6>Cumulative
(August 28, 2011 to April 21, 2012 )</TH></TR><TR class=bg-colour-yellow><TH id=ac2 colSpan=5 headers=ac1>Influenza A</TH><TH id=ac8 headers=ac1>B</TH><TH id=ac10 colSpan=5 headers=ac9>Influenza A</TH><TH id=ac16 headers=ac9>B</TH></TR><TR class=bg-colour-yellow><TH id=ac3 headers="ac1 ac2">A Total</TH><TH id=ac4 headers="ac1 ac2">A(H1)</TH><TH id=ac5 headers="ac1 ac2">A(H3)</TH><TH id=ac6 headers="ac1 ac2">Pand H1N1</TH><TH id=ac7 class=noWrap headers="ac1 ac2">A
( <ABBR title=unsubtyped>Un S</ABBR>)*</TH><TH headers="ac1 ac8">Total</TH><TH id=ac11 headers="ac9 ac10">A Total</TH><TH id=ac12 headers="ac9 ac10">A(H1)</TH><TH id=ac13 headers="ac9 ac10">A(H3)</TH><TH id=ac14 headers="ac9 ac10">Pand H1N1</TH><TH id=ac15 class=noWrap headers="ac9 ac10">A
(Un S) *</TH><TH headers="ac9 ac16">Total</TH></TR></THEAD><TFOOT><TR><TD id=ar13 class=fontSize85 colSpan=13 headers=ar1>* Unsubtyped: The specimen was typed as influenza A, but no test for subtyping was performed. Specimens from <ABBR title=Nunavut>NT</ABBR>, <ABBR title=Yukon>YT</ABBR>, and <ABBR title=Nunavut>NU</ABBR> 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.</TD></TR></TFOOT><TBODY><TR><TH id=ar2 class=bg-colour-yellow headers=ar1><ABBR title="British Columbia ">BC</ABBR></TH><TD class=alignCenter headers="ar1 ar2 ac1 ac2 ac3">28 </TD><TD class=alignCenter headers="ar1 ar2 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar2 ac1 ac2 ac5">18 </TD><TD class=alignCenter headers="ar1 ar2 ac1 ac2 ac6">9 </TD><TD class=alignCenter headers="ar1 ar2 ac1 ac2 ac7">1 </TD><TD class=alignCenter headers="ar1 ar2 ac1 ac8">5 </TD><TD class=alignCenter headers="ar1 ar2 ac9 ac10 ac11">532 </TD><TD class=alignCenter headers="ar1 ar2 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar2 ac9 ac10 ac13">429 </TD><TD class=alignCenter headers="ar1 ar2 ac9 ac10 ac14">90 </TD><TD class=alignCenter headers="ar1 ar2 ac9 ac10 ac15">13 </TD><TD class=alignCenter headers="ar1 ar2 ac9 ac16">90 </TD></TR><TR><TH id=ar3 class=bg-colour-yellow headers=ar1><ABBR title=Alberta>AB</ABBR></TH><TD class=alignCenter headers="ar1 ar3 ac1 ac2 ac3">92 </TD><TD class=alignCenter headers="ar1 ar3 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar3 ac1 ac2 ac5">63 </TD><TD class=alignCenter headers="ar1 ar3 ac1 ac2 ac6">12 </TD><TD class=alignCenter headers="ar1 ar3 ac1 ac2 ac7">17 </TD><TD class=alignCenter headers="ar1 ar3 ac1 ac8">22 </TD><TD class=alignCenter headers="ar1 ar3 ac9 ac10 ac11">1191 </TD><TD class=alignCenter headers="ar1 ar3 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar3 ac9 ac10 ac13">943 </TD><TD class=alignCenter headers="ar1 ar3 ac9 ac10 ac14">191 </TD><TD class=alignCenter headers="ar1 ar3 ac9 ac10 ac15">57 </TD><TD class=alignCenter headers="ar1 ar3 ac9 ac16">164 </TD></TR><TR><TH id=ar4 class=bg-colour-yellow headers=ar1><ABBR title=Saskatchewan>SK</ABBR></TH><TD class=alignCenter headers="ar1 ar4 ac1 ac2 ac3">17 </TD><TD class=alignCenter headers="ar1 ar4 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar4 ac1 ac2 ac5">8 </TD><TD class=alignCenter headers="ar1 ar4 ac1 ac2 ac6">2 </TD><TD class=alignCenter headers="ar1 ar4 ac1 ac2 ac7">7 </TD><TD class=alignCenter headers="ar1 ar4 ac1 ac8">9 </TD><TD class=alignCenter headers="ar1 ar4 ac9 ac10 ac11">494 </TD><TD class=alignCenter headers="ar1 ar4 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar4 ac9 ac10 ac13">311 </TD><TD class=alignCenter headers="ar1 ar4 ac9 ac10 ac14">47 </TD><TD class=alignCenter headers="ar1 ar4 ac9 ac10 ac15">136 </TD><TD class=alignCenter headers="ar1 ar4 ac9 ac16">62 </TD></TR><TR><TH id=ar5 class=bg-colour-yellow headers=ar1><ABBR title=Manitoba>MB</ABBR></TH><TD class=alignCenter headers="ar1 ar5 ac1 ac2 ac3">4 </TD><TD class=alignCenter headers="ar1 ar5 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar5 ac1 ac2 ac5">0 </TD><TD class=alignCenter headers="ar1 ar5 ac1 ac2 ac6">4 </TD><TD class=alignCenter headers="ar1 ar5 ac1 ac2 ac7">0 </TD><TD class=alignCenter headers="ar1 ar5 ac1 ac8">7 </TD><TD class=alignCenter headers="ar1 ar5 ac9 ac10 ac11">68 </TD><TD class=alignCenter headers="ar1 ar5 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar5 ac9 ac10 ac13">8 </TD><TD class=alignCenter headers="ar1 ar5 ac9 ac10 ac14">7 </TD><TD class=alignCenter headers="ar1 ar5 ac9 ac10 ac15">53 </TD><TD class=alignCenter headers="ar1 ar5 ac9 ac16">192 </TD></TR><TR><TH id=ar6 class=bg-colour-yellow headers=ar1><ABBR title=Ontario>ON</ABBR></TH><TD class=alignCenter headers="ar1 ar6 ac1 ac2 ac3">25 </TD><TD class=alignCenter headers="ar1 ar6 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar6 ac1 ac2 ac5">5 </TD><TD class=alignCenter headers="ar1 ar6 ac1 ac2 ac6">10 </TD><TD class=alignCenter headers="ar1 ar6 ac1 ac2 ac7">10 </TD><TD class=alignCenter headers="ar1 ar6 ac1 ac8">158 </TD><TD class=alignCenter headers="ar1 ar6 ac9 ac10 ac11">870 </TD><TD class=alignCenter headers="ar1 ar6 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar6 ac9 ac10 ac13">218 </TD><TD class=alignCenter headers="ar1 ar6 ac9 ac10 ac14">470 </TD><TD class=alignCenter headers="ar1 ar6 ac9 ac10 ac15">182 </TD><TD class=alignCenter headers="ar1 ar6 ac9 ac16">2356 </TD></TR><TR><TH id=ar7 class=bg-colour-yellow headers=ar1><ABBR title=Quebec>QC</ABBR>
</TH><TD class=alignCenter headers="ar1 ar7 ac1 ac2 ac3">82 </TD><TD class=alignCenter headers="ar1 ar7 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar7 ac1 ac2 ac5">7 </TD><TD class=alignCenter headers="ar1 ar7 ac1 ac2 ac6">0 </TD><TD class=alignCenter headers="ar1 ar7 ac1 ac2 ac7">75 </TD><TD class=alignCenter headers="ar1 ar7 ac1 ac8">190 </TD><TD class=alignCenter headers="ar1 ar7 ac9 ac10 ac11">1670 </TD><TD class=alignCenter headers="ar1 ar7 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar7 ac9 ac10 ac13">56 </TD><TD class=alignCenter headers="ar1 ar7 ac9 ac10 ac14">92 </TD><TD class=alignCenter headers="ar1 ar7 ac9 ac10 ac15">1522 </TD><TD class=alignCenter headers="ar1 ar7 ac9 ac16">1837 </TD></TR><TR><TH id=ar8 class=bg-colour-yellow headers=ar1><ABBR title="New Brunswick">NB</ABBR>
</TH><TD class=alignCenter headers="ar1 ar8 ac1 ac2 ac3">6 </TD><TD class=alignCenter headers="ar1 ar8 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar8 ac1 ac2 ac5">0 </TD><TD class=alignCenter headers="ar1 ar8 ac1 ac2 ac6">5 </TD><TD class=alignCenter headers="ar1 ar8 ac1 ac2 ac7">1 </TD><TD class=alignCenter headers="ar1 ar8 ac1 ac8">57 </TD><TD class=alignCenter headers="ar1 ar8 ac9 ac10 ac11">62 </TD><TD class=alignCenter headers="ar1 ar8 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar8 ac9 ac10 ac13">17 </TD><TD class=alignCenter headers="ar1 ar8 ac9 ac10 ac14">26 </TD><TD class=alignCenter headers="ar1 ar8 ac9 ac10 ac15">19 </TD><TD class=alignCenter headers="ar1 ar8 ac9 ac16">240 </TD></TR><TR><TH id=ar9 class=bg-colour-yellow headers=ar1><ABBR title="Nova Scotia ">NS</ABBR>
</TH><TD class=alignCenter headers="ar1 ar9 ac1 ac2 ac3">3 </TD><TD class=alignCenter headers="ar1 ar9 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar9 ac1 ac2 ac5">2 </TD><TD class=alignCenter headers="ar1 ar9 ac1 ac2 ac6">0 </TD><TD class=alignCenter headers="ar1 ar9 ac1 ac2 ac7">1 </TD><TD class=alignCenter headers="ar1 ar9 ac1 ac8">4 </TD><TD class=alignCenter headers="ar1 ar9 ac9 ac10 ac11">14 </TD><TD class=alignCenter headers="ar1 ar9 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar9 ac9 ac10 ac13">9 </TD><TD class=alignCenter headers="ar1 ar9 ac9 ac10 ac14">1 </TD><TD class=alignCenter headers="ar1 ar9 ac9 ac10 ac15">4 </TD><TD class=alignCenter headers="ar1 ar9 ac9 ac16">88 </TD></TR><TR><TH id=ar10 class=bg-colour-yellow headers=ar1><ABBR title="Prince Edward Island ">PE</ABBR>
</TH><TD class=alignCenter headers="ar1 ar10 ac1 ac2 ac3">0 </TD><TD class=alignCenter headers="ar1 ar10 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar10 ac1 ac2 ac5">0 </TD><TD class=alignCenter headers="ar1 ar10 ac1 ac2 ac6">0 </TD><TD class=alignCenter headers="ar1 ar10 ac1 ac2 ac7">0 </TD><TD class=alignCenter headers="ar1 ar10 ac1 ac8">7 </TD><TD class=alignCenter headers="ar1 ar10 ac9 ac10 ac11">3 </TD><TD class=alignCenter headers="ar1 ar10 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar10 ac9 ac10 ac13">2 </TD><TD class=alignCenter headers="ar1 ar10 ac9 ac10 ac14">1 </TD><TD class=alignCenter headers="ar1 ar10 ac9 ac10 ac15">0 </TD><TD class=alignCenter headers="ar1 ar10 ac9 ac16">38 </TD></TR><TR><TH id=ar11 class=bg-colour-yellow headers=ar1><ABBR title="Newfoundland/Labrador ">NL</ABBR>
</TH><TD class=alignCenter headers="ar1 ar11 ac1 ac2 ac3">12 </TD><TD class=alignCenter headers="ar1 ar11 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar11 ac1 ac2 ac5">0 </TD><TD class=alignCenter headers="ar1 ar11 ac1 ac2 ac6">1 </TD><TD class=alignCenter headers="ar1 ar11 ac1 ac2 ac7">11 </TD><TD class=alignCenter headers="ar1 ar11 ac1 ac8">3 </TD><TD class=alignCenter headers="ar1 ar11 ac9 ac10 ac11">71 </TD><TD class=alignCenter headers="ar1 ar11 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar11 ac9 ac10 ac13">30 </TD><TD class=alignCenter headers="ar1 ar11 ac9 ac10 ac14">10 </TD><TD class=alignCenter headers="ar1 ar11 ac9 ac10 ac15">31 </TD><TD class=alignCenter headers="ar1 ar11 ac9 ac16">198 </TD></TR><TR><TH id=ar12 class=bg-colour-yellow headers=ar1>Canada</TH><TD class=alignCenter headers="ar1 ar12 ac1 ac2 ac3">269 </TD><TD class=alignCenter headers="ar1 ar12 ac1 ac2 ac4">0 </TD><TD class=alignCenter headers="ar1 ar12 ac1 ac2 ac5">103 </TD><TD class=alignCenter headers="ar1 ar12 ac1 ac2 ac6">43 </TD><TD class=alignCenter headers="ar1 ar12 ac1 ac2 ac7">123 </TD><TD class=alignCenter headers="ar1 ar12 ac1 ac8">462 </TD><TD class=alignCenter headers="ar1 ar12 ac9 ac10 ac11">4975 </TD><TD class=alignCenter headers="ar1 ar12 ac9 ac10 ac12">0 </TD><TD class=alignCenter headers="ar1 ar12 ac9 ac10 ac13">2023 </TD><TD class=alignCenter headers="ar1 ar12 ac9 ac10 ac14">935 </TD><TD class=alignCenter headers="ar1 ar12 ac9 ac10 ac15">2017 </TD><TD class=alignCenter headers="ar1 ar12 ac9 ac16">5265 </TD></TR></TBODY></TABLE>
<TABLE class=widthFull border=1 cellSpacing=0 cellPadding=2><CAPTION>Table 2. Weekly & Cumulative numbers of positive influenza specimens by age groups
reported through case-based laboratory reporting, Canada, 2011-2012 *</CAPTION><THEAD><TR class=bg-colour-yellow><TH id=br1 rowSpan=3>Age groups</TH><TH id=bc1 colSpan=5>Weekly
April 15 to April 21, 2012 </TH><TH id=bc8 colSpan=5>Cumulative
(Aug. 28, 2011 to April 21, 2012 )</TH></TR><TR class=bg-colour-yellow><TH id=bc2 colSpan=4 headers=bc1>Influenza A</TH><TH id=bc7 headers=bc1>B</TH><TH id=bc9 colSpan=4 headers=bc8>Influenza A</TH><TH id=bc14 headers=bc8>B</TH></TR><TR class=bg-colour-yellow><TH id=bc3 headers="bc1 bc2">A Total</TH><TH id=bc4 headers="bc1 bc2">Pandemic H1N1</TH><TH id=bc5 headers="bc1 bc2">A/H3N2</TH><TH id=bc6 headers="bc1 bc2">A unsubtyped</TH><TH headers="bc1 bc7">Total</TH><TH id=bc10 headers="bc8 bc9">A Total</TH><TH id=bc11 headers="bc8 bc9">Pandemic H1N1</TH><TH id=bc12 headers="bc8 bc9">A/H3N2</TH><TH id=bc13 headers="bc8 bc9">A unsubtyped</TH><TH headers="bc8 bc14">Total</TH></TR></THEAD><TFOOT><TR><TD id=br9 class=fontSize85 colSpan=11 headers=br1>* Please note that this table reflects the number of specimens for which demographic information was reported.
These represent a subset of all positive influenza cases reported. Delays in the reporting of data may cause data to change retrospectively.</TD></TR></TFOOT><TBODY><TR><TH id=br2 headers=br1>< 5</TH><TD class=alignCenter headers="br1 br2 bc1 bc2 bc3">31 </TD><TD class=alignCenter headers="br1 br2 bc1 bc2 bc4">5 </TD><TD class=alignCenter headers="br1 br2 bc1 bc2 bc5">10 </TD><TD class=alignCenter headers="br1 br2 bc1 bc2 bc6">16 </TD><TD class=alignCenter headers="br1 br2 bc1 bc7">46 </TD><TD class=alignCenter headers="br1 br2 bc8 bc9 bc10">894 </TD><TD class=alignCenter headers="br1 br2 bc8 bc9 bc11">193 </TD><TD class=alignCenter headers="br1 br2 bc8 bc9 bc12">318 </TD><TD class=alignCenter headers="br1 br2 bc8 bc9 bc13">383 </TD><TD class=alignCenter headers="br1 br2 bc8 bc14">934 </TD></TR><TR><TH id=br3 headers=br1>5-19</TH><TD class=alignCenter headers="br1 br3 bc1 bc2 bc3">16 </TD><TD class=alignCenter headers="br1 br3 bc1 bc2 bc4">0 </TD><TD class=alignCenter headers="br1 br3 bc1 bc2 bc5">5 </TD><TD class=alignCenter headers="br1 br3 bc1 bc2 bc6">11 </TD><TD class=alignCenter headers="br1 br3 bc1 bc7">38 </TD><TD class=alignCenter headers="br1 br3 bc8 bc9 bc10">518 </TD><TD class=alignCenter headers="br1 br3 bc8 bc9 bc11">74 </TD><TD class=alignCenter headers="br1 br3 bc8 bc9 bc12">261 </TD><TD class=alignCenter headers="br1 br3 bc8 bc9 bc13">183 </TD><TD class=alignCenter headers="br1 br3 bc8 bc14">1032 </TD></TR><TR><TH id=br4 headers=br1>20-44</TH><TD class=alignCenter headers="br1 br4 bc1 bc2 bc3">24 </TD><TD class=alignCenter headers="br1 br4 bc1 bc2 bc4">5 </TD><TD class=alignCenter headers="br1 br4 bc1 bc2 bc5">8 </TD><TD class=alignCenter headers="br1 br4 bc1 bc2 bc6">11 </TD><TD class=alignCenter headers="br1 br4 bc1 bc7">44 </TD><TD class=alignCenter headers="br1 br4 bc8 bc9 bc10">1170 </TD><TD class=alignCenter headers="br1 br4 bc8 bc9 bc11">253 </TD><TD class=alignCenter headers="br1 br4 bc8 bc9 bc12">430 </TD><TD class=alignCenter headers="br1 br4 bc8 bc9 bc13">487 </TD><TD class=alignCenter headers="br1 br4 bc8 bc14">765 </TD></TR><TR><TH id=br5 headers=br1>45-64</TH><TD class=alignCenter headers="br1 br5 bc1 bc2 bc3">26 </TD><TD class=alignCenter headers="br1 br5 bc1 bc2 bc4">6 </TD><TD class=alignCenter headers="br1 br5 bc1 bc2 bc5">7 </TD><TD class=alignCenter headers="br1 br5 bc1 bc2 bc6">13 </TD><TD class=alignCenter headers="br1 br5 bc1 bc7">40 </TD><TD class=alignCenter headers="br1 br5 bc8 bc9 bc10">792 </TD><TD class=alignCenter headers="br1 br5 bc8 bc9 bc11">164 </TD><TD class=alignCenter headers="br1 br5 bc8 bc9 bc12">268 </TD><TD class=alignCenter headers="br1 br5 bc8 bc9 bc13">360 </TD><TD class=alignCenter headers="br1 br5 bc8 bc14">529 </TD></TR><TR><TH id=br6 headers=br1>65+</TH><TD class=alignCenter headers="br1 br6 bc1 bc2 bc3">67 </TD><TD class=alignCenter headers="br1 br6 bc1 bc2 bc4">0 </TD><TD class=alignCenter headers="br1 br6 bc1 bc2 bc5">30 </TD><TD class=alignCenter headers="br1 br6 bc1 bc2 bc6">37 </TD><TD class=alignCenter headers="br1 br6 bc1 bc7">85 </TD><TD class=alignCenter headers="br1 br6 bc8 bc9 bc10">1076 </TD><TD class=alignCenter headers="br1 br6 bc8 bc9 bc11">64 </TD><TD class=alignCenter headers="br1 br6 bc8 bc9 bc12">659 </TD><TD class=alignCenter headers="br1 br6 bc8 bc9 bc13">353 </TD><TD class=alignCenter headers="br1 br6 bc8 bc14">896 </TD></TR><TR><TH id=br7 headers=br1>Unknown</TH><TD class=alignCenter headers="br1 br7 bc1 bc2 bc3">0 </TD><TD class=alignCenter headers="br1 br7 bc1 bc2 bc4">0 </TD><TD class=alignCenter headers="br1 br7 bc1 bc2 bc5">0 </TD><TD class=alignCenter headers="br1 br7 bc1 bc2 bc6">0 </TD><TD class=alignCenter headers="br1 br7 bc1 bc7">0 </TD><TD class=alignCenter headers="br1 br7 bc8 bc9 bc10">18 </TD><TD class=alignCenter headers="br1 br7 bc8 bc9 bc11">6 </TD><TD class=alignCenter headers="br1 br7 bc8 bc9 bc12">11 </TD><TD class=alignCenter headers="br1 br7 bc8 bc9 bc13">1 </TD><TD class=alignCenter headers="br1 br7 bc8 bc14">3 </TD></TR><TR><TH id=br8 headers=br1>Total</TH><TD class=alignCenter headers="br1 br8 bc1 bc2 bc3">164 </TD><TD class=alignCenter headers="br1 br8 bc1 bc2 bc4">16 </TD><TD class=alignCenter headers="br1 br8 bc1 bc2 bc5">60 </TD><TD class=alignCenter headers="br1 br8 bc1 bc2 bc6">88 </TD><TD class=alignCenter headers="br1 br8 bc1 bc7">253 </TD><TD class=alignCenter headers="br1 br8 bc8 bc9 bc10">4468 </TD><TD class=alignCenter headers="br1 br8 bc8 bc9 bc11">754 </TD><TD class=alignCenter headers="br1 br8 bc8 bc9 bc12">1947 </TD><TD class=alignCenter headers="br1 br8 bc8 bc9 bc13">1767 </TD><TD class=alignCenter headers="br1 br8 bc8 bc14">4159 </TD></TR></TBODY></TABLE>
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Figure 4. Influenza tests reported and percentage of tests positive, Canada,
by report week, 2011-2012
Text equivalent for figure 4Influenza tests reported and percentage of tests positive, Canada, by report week, 2011-2012
Figure 5. Percent positive influenza tests, compared to other respiratory viruses,
Canada, by reporting week, 2011-2012
Text equivalent for figure 5Percent positive influenza tests, compared to other respiratory viruses, Canada, by reporting week, 2011-2012
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Influenza strain characterizations
Since the start of the season, the National Microbiology Laboratory (<ABBR title="National Microbiology Laboratory">NML</ABBR>) has antigenically characterized 969 influenza viruses (189 A/H3N2, 178 A/H1N1 and 602 B). Of the 189 A/H3N2 viruses (from BC, AB, SK, MB, ON, QC, NS & NT), 170 (90.0%) were antigenically similar to A/Perth/16/2009 while 19 (10.0%) viruses showed reduced titers with antiserum produced against A/Perth/16/2009. Of the 178 A/H1N1 viruses characterized (from BC, AB, SK, MB, ON, QC & NB), 173 (97.2%) were antigenically similar to A/California/07/2009 and 5 (2.8%) viruses tested showed reduced titer with antiserum produced against A/California/07/2009. Of the 602 influenza B viruses characterized, 306 (50.8%) (from BC, AB, SK, MB, ON, QC, NB, NS & NL) were antigenically similar to the vaccine strain B/Brisbane/60/2008 (Victoria lineage); however 1 virus out of the 306 tested showed reduced titer with antiserum produced against B/Brisbane/60/2008. The remaining 296 (49.2%) influenza B viruses (from BC, AB, MB, ON, QC, NB, NS & NU) are antigenically related to the reference virus B/Wisconsin/01/2010-like, which belongs to the Yamagata lineage. (Figure 6)
Figure 6. Influenza strain characterizations, Canada, 2011-2012, N = 969
Note: The recommended components for the 2011-2012 Northern Hemisphere influenza vaccine include: A/Perth/16/2009 (H3N2), A/California/7/2009 (H1N1) and B/Brisbane/60/2008.
Text equivalent for figure 6Influenza strain characterizations, Canada, 2011-2012
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Antiviral resistance
Since the beginning of the season, NML has tested 937 influenza viruses for resistance to oseltamivir (by phenotypic assay and/or sequencing) and 936 for zanamivir (by phenotypic assay) and it was found that all viruses tested were susceptible to oseltamivir and zanamivir. A total of 558 influenza A viruses (309 H3N2 and 249 H1N1) were tested for amantadine resistance; all but 1 influenza A(H3N2) virus tested were resistant. (Table 3)
<TABLE class=widthFull border=1 cellSpacing=0 cellPadding=2><CAPTION>Table 3. Antiviral resistance by influenza virus type and subtype, Canada, 2011-2012 </CAPTION><THEAD><TR class=bg-colour-yellow><TH id=cr1 rowSpan=2>Virus type and subtype</TH><TH id=cc1 colSpan=2>Oseltamivir</TH><TH id=cc4 colSpan=2>Zanamivir</TH><TH id=cc7 colSpan=2>Amantadine</TH></TR><TR class=bg-colour-yellow><TH id=cc2 headers=cc1># tested</TH><TH id=cc3 headers=cc1># resistant (%)</TH><TH id=cc5 headers=cc4># tested</TH><TH id=cc6 headers=cc4># resistant (%)</TH><TH id=cc8 headers=cc7># tested</TH><TH id=cc9 headers=cc7># resistant (%)</TH></TR></THEAD><TFOOT><TR><TD id=cr6 class=fontSize85 colSpan=7 headers=cr1><SUP>*</SUP> NA - not applicable</TD></TR></TFOOT><TBODY><TR><TH id=cr2 class="alignLeft bg-colour-blue" headers=cr1>A (H3N2)</TH><TD class=alignCenter headers="cr1 cr2 cc1 cc2">182 </TD><TD class=alignCenter headers="cr1 cr2 cc1 cc3">0 </TD><TD class=alignCenter headers="cr1 cr2 cc4 cc5">183 </TD><TD class=alignCenter headers="cr1 cr2 cc4 cc6">0 </TD><TD class=alignCenter headers="cr1 cr2 cc7 cc8">309 </TD><TD class=alignCenter headers="cr1 cr2 cc7 cc9">308 (99.7%) </TD></TR><TR><TH id=cr3 class="alignLeft bg-colour-blue" headers=cr1>A (H1N1)</TH><TD class=alignCenter headers="cr1 cr3 cc1 cc2">190 </TD><TD class=alignCenter headers="cr1 cr3 cc1 cc3">0 </TD><TD class=alignCenter headers="cr1 cr3 cc4 cc5">190 </TD><TD class=alignCenter headers="cr1 cr3 cc4 cc6">0 </TD><TD class=alignCenter headers="cr1 cr3 cc7 cc8">249 </TD><TD class=alignCenter headers="cr1 cr3 cc7 cc9">249 (100%) </TD></TR><TR><TH id=cr4 class="alignLeft bg-colour-blue" headers=cr1>B</TH><TD class=alignCenter headers="cr1 cr4 cc1 cc2">565 </TD><TD class=alignCenter headers="cr1 cr4 cc1 cc3">0 </TD><TD class=alignCenter headers="cr1 cr4 cc4 cc5">565 </TD><TD class=alignCenter headers="cr1 cr4 cc4 cc6">0 </TD><TD class=alignCenter headers="cr1 cr4 cc7 cc8">NA* </TD><TD class=alignCenter headers="cr1 cr4 cc7 cc9">NA* </TD></TR><TR><TH id=cr5 class="alignLeft bg-colour-blue" headers=cr1>TOTAL</TH><TD class=alignCenter headers="cr1 cr5 cc1 cc2">937 </TD><TD class=alignCenter headers="cr1 cr5 cc1 cc3">0 </TD><TD class=alignCenter headers="cr1 cr5 cc4 cc5">938 </TD><TD class=alignCenter headers="cr1 cr5 cc4 cc6">0 </TD><TD class=alignCenter headers="cr1 cr5 cc7 cc8">558 </TD><TD class=alignCenter headers="cr1 cr5 cc7 cc9">557 (99.8%) </TD></TR></TBODY></TABLE>
Influenza-like Illness (ILI) Consultation Rate
The national ILI consultation rate declined from the previous week (17.5 ILI consultations per 1,000 patient visits in week 16) but remains within the expected levels for this time of year (Figure 7). The highest consultation rates this week were observed children under 5 (41.4/1,000 visits) and in those between 5 to 19 years old (19.2/1,000 visits).
Figure 7. Influenza-like illness (ILI) consultation rates, Canada, by report week, 2011-2012 compared to 1996/97 through to 2010/11 seasons (with pandemic data suppressed)
Note: No data available for mean rate in previous years for weeks 19 to 39 (1996-1997 through 2002-2003 seasons). Delays in the reporting of data may cause data to change retrospectively.
Text equivalent for figure 7Influenza-like illness (ILI) consultation rates, Canada, by report week, 2011-2012 compared to 1996/97 through to 2010/11 seasons (with pandemic data suppressed)
Severe Respiratory Illness Surveillance
Paediatric Influenza Hospitalizations and Deaths (IMPACT)
In week 16, 18 new laboratory-confirmed influenza-associated paediatric (16 years of age and under) hospitalizations were reported through the Immunization Monitoring Program Active (IMPACT) network. Four hospitalizations were due to influenza A (unsubtyped) (in BC & QC); 1 was due to A(H3N2) (in AB), 1 was due to A(H1N1) (in AB) and 12 were due to influenza B (in AB, ON, QC & NS).
To date this season, 502 influenza-associated paediatric hospitalizations have been reported through IMPACT (from BC, AB, SK, MB, ON, QC, NS & NL); 223 (44.4%) were due to influenza A and 279 (55.6%) were due to influenza B. The proportion of cases by age group is as follows: 15.1% among infants <6 months of age; 20.9% among children 6-23 months of age; 31.5% were between 2-4 years; 22.1% were between 5-9 years; and 10.4% were between 10-16 years. To date this season, 4 influenza B associated deaths have been reported through the IMPACT network.
Note: The number of hospitalizations reported through IMPACT represents a subset of all influenza-associate paediatric hospitalizations in Canada; therefore, the number of hospitalizations included in this report may differ from those reported by other Provincial and Territorial Health Authorities.
Influenza Hospitalizations and Deaths (Aggregate Surveillance System)
In week 16, 123 new laboratory-confirmed influenza-associated hospitalizations were reported of which 35 (28.5%) were in those < 20 years of age and 88 (71.5%) in those ≥ 20 years of age; 24.4% due to influenza A and 75.6% due to influenza B. The hospitalizations were reported in AB (10), MB (5), ON (103), PE (1) and NL (4). Of the 123 hospitalizations, 1 required admission to ICU (MB) and was associated with influenza A(H1N1)pmd09 infection. In addition, there were 5 adult influenza-associated deaths reported (in ON); all 5 deaths were associated with influenza B infection and all cases were ≥ 65 years of age.
To date this season, 1,354 influenza-associated hospitalizations have been reported from 7 provinces (AB, SK, MB, ON, NS, PE & NL) and 2 territories (YT & NT). The largest proportion of cases was observed in those > 65 years of age (32.3%). Influenza B (55.6%) continues to be the predominant influenza type among hospitalized cases compared to influenza A (44.4%); of those influenza A hospitalizations where subtype was available, influenza A(H3N2) predominated (57.9%). There have been 55 hospitalizations requiring ICU admission reported (from AB, SK, MB, NS & NL) of which 29.1% were < 20 years of age and 70.9% were ≥ 20 years of age. To date this season, 76 influenza-associated deaths have been reported (from AB, SK, MB, ON & NS) of which 6.6% were among those < 20 years of age and 93.4% in those ≥ 20 years of age. Of the adult deaths, 78.9% were in those ≥ 65 years of age.
Note: Some of the hospitalizations and deaths reported in those < 16 years of age may also have been reported in the IMPACT summary above if the hospitalization or death occurred in one of the 12 IMPACT hospitals. The reason for hospitalization or cause of death does not have to be attributable to influenza in order to be reported. Influenza-associated hospitalizations are not reported to PHAC by the following Provinces: BC, & QC. Only hospitalizations that require intensive medical care are reported by SK. ICU admissions are not reported in ON.
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