FluWatch report: March 9 to 15, 2014 (Week 11)
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Overall Summary
- In week 11, influenza activity in Canada has increased slightly, with the majority of influenza viruses detected being influenza B. Overall, the influenza A(H1N1) virus remains the most common influenza virus circulating this season, and influenza activity remains within expected levels for this time of year.
- While the influenza A(H1N1) virus has mostly affected adults 20-64 years of age this season, influenza B is having a greater impact on adults 65 years of age and older, as well as young persons 5 to 19 years of age.
- As of week 11, 3,570 hospitalizations and 197 deaths have been reported from participating regions, which is comparable to reports in past influenza seasons.
- A Public Health Agency of Canada survey, conducted in February 2014, estimates that 39% of the Canadian population received the 2013-14 seasonal influenza vaccine, with higher coverage of 69.5% in Canadians aged 65 years and older.
Influenza/ILI Activity (geographic spread)
In week 11, influenza activity levels increased slightly. One region in Quebec reported widespread activity and nine regions (BC(1), ON(5), and QC(3)) reported localized activity (Figure 1).
Figure 1. Map of overall influenza/ILI activity level by province and territory, Canada, Week 11
Note: Influenza/ILI 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 and reported outbreaks. Please refer to detailed definitions at the end of the report. Maps from previous weeks, including any retrospective updates, are available on the FluWatch website.
Text equivalent for figure 1Map of overall Influenza activity level by province and territory, Canada
Influenza and Other Respiratory Virus Detections
The number of positive influenza tests increased slightly, from 743 in week 10 to 750 in week 11, driven by increasing detections of influenza B. The percentage of positive influenza tests increased from 12.3% in week 10 to 13.4% in week 11, with 65% of positive tests being influenza B (Figure 2). The highest percentages of influenza B among positive tests have been reported from Newfoundland & Labrador (29.2%) and Quebec (23.8%), followed by Ontario (11.1%) and British Columbia (8.1%). Despite the late-season circulation of influenza B, the predominant influenza virus this season remains A(H1N1)pdm09 (Table 1). Among the 18,962 cases for which information on age and type/subtype has been received this season, 54.9% were 20-64 years of age (Table 2). Significantly greater proportions of influenza B cases have been ≥65 years of age and 5-19 years of age compared to cases of A(H1N1)pdm09.
Figure 2. Number of positive influenza tests and percentage of tests positive, by type, subtype and report week, Canada, 2013-14
Text equivalent for figure 2Number of positive influenza tests and percentage of tests positive, by type, subtype and report week, Canada, 2013-14
The number of positive tests for RSV has been declining gradually over recent weeks, similar to the trend observed in recent seasons. The number of positive tests for parainfluenza was stable in week 11 and has been on a downward trend since week 02. The number of positive tests for adenovirus and rhinovirus have decreased in recent weeks; and in week 11, detections of coronavirus resumed a decline that started in week 05. The number of positive tests for human metapneumovirus has been higher than during the same period last season and has been similar over the past 5 weeks (Figure 3).
For more details, see the weekly Respiratory Virus Detections in Canada Report.
Figure 3. Number of positive laboratory tests for other respiratory viruses by report week, Canada, 2013-14
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RSV: Respiratory syncytial virus; hMPV: Human metapneumovirus
Text equivalent for figure 3Overall Number of Influenza Outbreaks, Canada, by Report Week, 2013-2014
<TABLE id=t1 class=widthFull border=1 cellSpacing=0 cellPadding=2><CAPTION class=alignCenter>Table 1: Weekly and cumulative numbers of positive influenza specimens
by type, subtype and province, Canada, 2013-14</CAPTION><THEAD><TR class=bg-colour-yellow><TH id=ar1 rowSpan=3>Reporting provinces <SUP>1</SUP></TH><TH id=ac1 colSpan=5>Weekly
(March 9, 2013 to March 15, 2014)</TH><TH id=ac8 colSpan=5>Cumulative
(August 25, 2013 to March 15, 2014)</TH></TR><TR class=bg-colour-yellow><TH id=ac2 colSpan=4 headers=ac1>Influenza A</TH><TH id=ac7 headers=ac1>B</TH><TH id=ac9 colSpan=4 headers=ac8>Influenza A</TH><TH id=ac14 headers=ac8>B</TH></TR><TR class=bg-colour-grey-light><TH id=ac3 headers="ac1 ac2">A Total</TH><TH id=ac4 class=lightred headers="ac1 ac2">A(H1)pdm09</TH><TH id=ac5 class=lightred headers="ac1 ac2">A(H3)</TH><TH id=ac6 class=lightred headers="ac1 ac2">A(UnS)</TH><TH class=alignCenter headers="ac1 ac7">B Total</TH><TH id=ac10 headers="ac8 ac9">A Total</TH><TH id=ac11 class=lightred headers="ac8 ac9">A(H1)pdm09</TH><TH id=ac12 class=lightred headers="ac8 ac9">A(H3)</TH><TH id=ac13 class=lightred headers="ac8 ac9">A(UnS)</TH><TD class=alignCenter headers="ac8 ac14">B Total</TD></TR></THEAD><TFOOT><TR><TD class=fontSize85 colSpan=11><SUP>1 </SUP>Specimens from NT, YT, and NU are sent to reference laboratories in other provinces. Cumulative data includes updates to previous weeks.
<SUP>2 </SUP>Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.</TD></TR></TFOOT><TBODY><TR><TH id=ar2 class=alignLeft headers=ar1>BC</TH><TD class=alignRight headers="ar1 ar2 ac1 ac2 ac3">30</TD><TD class=alignRight headers="ar1 ar2 ac1 ac2 ac4">18</TD><TD class=alignRight headers="ar1 ar2 ac1 ac2 ac5">6</TD><TD class=alignRight headers="ar1 ar2 ac1 ac2 ac6">6</TD><TD class=alignRight headers="ar1 ar2 ac1 ac7">33</TD><TD class=alignRight headers="ar1 ar2 ac8 ac9 ac10">1755</TD><TD class=alignRight headers="ar1 ar2 ac8 ac9 ac11">1592</TD><TD class=alignRight headers="ar1 ar2 ac8 ac9 ac12">50</TD><TD class=alignRight headers="ar1 ar2 ac8 ac9 ac13">113</TD><TD class=alignRight headers="ar1 ar2 ac8 ac14">155</TD></TR><TR><TH id=ar3 class=alignLeft headers=ar1>AB</TH><TD class=alignRight headers="ar1 ar3 ac1 ac2 ac3">46</TD><TD class=alignRight headers="ar1 ar3 ac1 ac2 ac4">5</TD><TD class=alignRight headers="ar1 ar3 ac1 ac2 ac5">4</TD><TD class=alignRight headers="ar1 ar3 ac1 ac2 ac6">37</TD><TD class=alignRight headers="ar1 ar3 ac1 ac7">28</TD><TD class=alignRight headers="ar1 ar3 ac8 ac9 ac10">3719</TD><TD class=alignRight headers="ar1 ar3 ac8 ac9 ac11">3371</TD><TD class=alignRight headers="ar1 ar3 ac8 ac9 ac12">53</TD><TD class=alignRight headers="ar1 ar3 ac8 ac9 ac13">295</TD><TD class=alignRight headers="ar1 ar3 ac8 ac14">151</TD></TR><TR><TH id=ar4 class=alignLeft headers=ar1>SK</TH><TD class=alignRight headers="ar1 ar4 ac1 ac2 ac3">6</TD><TD class=alignRight headers="ar1 ar4 ac1 ac2 ac4">5</TD><TD class=alignRight headers="ar1 ar4 ac1 ac2 ac5">1</TD><TD class=alignRight headers="ar1 ar4 ac1 ac2 ac6">0</TD><TD class=alignRight headers="ar1 ar4 ac1 ac7">10</TD><TD class=alignRight headers="ar1 ar4 ac8 ac9 ac10">1349</TD><TD class=alignRight headers="ar1 ar4 ac8 ac9 ac11">972</TD><TD class=alignRight headers="ar1 ar4 ac8 ac9 ac12">6</TD><TD class=alignRight headers="ar1 ar4 ac8 ac9 ac13">371</TD><TD class=alignRight headers="ar1 ar4 ac8 ac14">44</TD></TR><TR><TH id=ar5 class=alignLeft headers=ar1>MB</TH><TD class=alignRight headers="ar1 ar5 ac1 ac2 ac3">27</TD><TD class=alignRight headers="ar1 ar5 ac1 ac2 ac4">24</TD><TD class=alignRight headers="ar1 ar5 ac1 ac2 ac5">0</TD><TD class=alignRight headers="ar1 ar5 ac1 ac2 ac6">3</TD><TD class=alignRight headers="ar1 ar5 ac1 ac7">0</TD><TD class=alignRight headers="ar1 ar5 ac8 ac9 ac10">622</TD><TD class=alignRight headers="ar1 ar5 ac8 ac9 ac11">446</TD><TD class=alignRight headers="ar1 ar5 ac8 ac9 ac12">1</TD><TD class=alignRight headers="ar1 ar5 ac8 ac9 ac13">175</TD><TD class=alignRight headers="ar1 ar5 ac8 ac14">15</TD></TR><TR><TH id=ar6 class=alignLeft headers=ar1>ON</TH><TD class=alignRight headers="ar1 ar6 ac1 ac2 ac3">56</TD><TD class=alignRight headers="ar1 ar6 ac1 ac2 ac4">26</TD><TD class=alignRight headers="ar1 ar6 ac1 ac2 ac5">11</TD><TD class=alignRight headers="ar1 ar6 ac1 ac2 ac6">19</TD><TD class=alignRight headers="ar1 ar6 ac1 ac7">159</TD><TD class=alignRight headers="ar1 ar6 ac8 ac9 ac10">5488</TD><TD class=alignRight headers="ar1 ar6 ac8 ac9 ac11">2416</TD><TD class=alignRight headers="ar1 ar6 ac8 ac9 ac12">265</TD><TD class=alignRight headers="ar1 ar6 ac8 ac9 ac13">2807</TD><TD class=alignRight headers="ar1 ar6 ac8 ac14">682</TD></TR><TR><TH id=ar7 class=alignLeft headers=ar1>QC</TH><TD class=alignRight headers="ar1 ar7 ac1 ac2 ac3">80</TD><TD class=alignRight headers="ar1 ar7 ac1 ac2 ac4">7</TD><TD class=alignRight headers="ar1 ar7 ac1 ac2 ac5">0</TD><TD class=alignRight headers="ar1 ar7 ac1 ac2 ac6">73</TD><TD class=alignRight headers="ar1 ar7 ac1 ac7">242</TD><TD class=alignRight headers="ar1 ar7 ac8 ac9 ac10">5231</TD><TD class=alignRight headers="ar1 ar7 ac8 ac9 ac11">672</TD><TD class=alignRight headers="ar1 ar7 ac8 ac9 ac12">3</TD><TD class=alignRight headers="ar1 ar7 ac8 ac9 ac13">4556</TD><TD class=alignRight headers="ar1 ar7 ac8 ac14">1633</TD></TR><TR><TH id=ar8 class=alignLeft headers=ar1>NB</TH><TD class=alignRight headers="ar1 ar8 ac1 ac2 ac3">8</TD><TD class=alignRight headers="ar1 ar8 ac1 ac2 ac4">0</TD><TD class=alignRight headers="ar1 ar8 ac1 ac2 ac5">0</TD><TD class=alignRight headers="ar1 ar8 ac1 ac2 ac6">8</TD><TD class=alignRight headers="ar1 ar8 ac1 ac7">5</TD><TD class=alignRight headers="ar1 ar8 ac8 ac9 ac10">1488</TD><TD class=alignRight headers="ar1 ar8 ac8 ac9 ac11">370</TD><TD class=alignRight headers="ar1 ar8 ac8 ac9 ac12">1</TD><TD class=alignRight headers="ar1 ar8 ac8 ac9 ac13">1117</TD><TD class=alignRight headers="ar1 ar8 ac8 ac14">23</TD></TR><TR><TH id=ar9 class=alignLeft headers=ar1>NS</TH><TD class=alignRight headers="ar1 ar9 ac1 ac2 ac3">10</TD><TD class=alignRight headers="ar1 ar9 ac1 ac2 ac4">10</TD><TD class=alignRight headers="ar1 ar9 ac1 ac2 ac5">0</TD><TD class=alignRight headers="ar1 ar9 ac1 ac2 ac6">0</TD><TD class=alignRight headers="ar1 ar9 ac1 ac7">0</TD><TD class=alignRight headers="ar1 ar9 ac8 ac9 ac10">163</TD><TD class=alignRight headers="ar1 ar9 ac8 ac9 ac11">134</TD><TD class=alignRight headers="ar1 ar9 ac8 ac9 ac12">4</TD><TD class=alignRight headers="ar1 ar9 ac8 ac9 ac13">25</TD><TD class=alignRight headers="ar1 ar9 ac8 ac14">3</TD></TR><TR><TH id=ar10 class=alignLeft headers=ar1>PE</TH><TD class=alignRight headers="ar1 ar10 ac1 ac2 ac3">1</TD><TD class=alignRight headers="ar1 ar10 ac1 ac2 ac4">1</TD><TD class=alignRight headers="ar1 ar10 ac1 ac2 ac5">0</TD><TD class=alignRight headers="ar1 ar10 ac1 ac2 ac6">0</TD><TD class=alignRight headers="ar1 ar10 ac1 ac7">0</TD><TD class=alignRight headers="ar1 ar10 ac8 ac9 ac10">118</TD><TD class=alignRight headers="ar1 ar10 ac8 ac9 ac11">117</TD><TD class=alignRight headers="ar1 ar10 ac8 ac9 ac12">0</TD><TD class=alignRight headers="ar1 ar10 ac8 ac9 ac13">1</TD><TD class=alignRight headers="ar1 ar10 ac8 ac14">1</TD></TR><TR><TH id=ar11 class=alignLeft headers=ar1>NL</TH><TD class=alignRight headers="ar1 ar11 ac1 ac2 ac3">1</TD><TD class=alignRight headers="ar1 ar11 ac1 ac2 ac4">0</TD><TD class=alignRight headers="ar1 ar11 ac1 ac2 ac5">0</TD><TD class=alignRight headers="ar1 ar11 ac1 ac2 ac6">1</TD><TD class=alignRight headers="ar1 ar11 ac1 ac7">8</TD><TD class=alignRight headers="ar1 ar11 ac8 ac9 ac10">340</TD><TD class=alignRight headers="ar1 ar11 ac8 ac9 ac11">104</TD><TD class=alignRight headers="ar1 ar11 ac8 ac9 ac12">0</TD><TD class=alignRight headers="ar1 ar11 ac8 ac9 ac13">236</TD><TD class=alignRight headers="ar1 ar11 ac8 ac14">140</TD></TR><TR><TH id=ar12 class=alignLeft headers=ar1>Canada</TH><TD class=alignRight headers="ar1 ar12 ac1 ac2 ac3">265</TD><TD class="alignRight lightred" headers="ar1 ar12 ac1 ac2 ac4">96</TD><TD class="alignRight lightred" headers="ar1 ar12 ac1 ac2 ac5">22</TD><TD class="alignRight lightred" headers="ar1 ar12 ac1 ac2 ac6">147</TD><TD class=alignRight headers="ar1 ar12 ac1 ac7">485</TD><TD class=alignRight headers="ar1 ar12 ac8 ac9 ac10">20273</TD><TD class="alignRight lightred" headers="ar1 ar12 ac8 ac9 ac11">10194</TD><TD class="alignRight lightred" headers="ar1 ar12 ac8 ac9 ac12">383</TD><TD class="alignRight lightred" headers="ar1 ar12 ac8 ac9 ac13">9696</TD><TD class=alignRight headers="ar1 ar12 ac8 ac14">2847</TD></TR><TR><TH id=ar13 class=alignLeft headers=ar1>Percentage<SUP>2</SUP></TH><TD class=alignRight headers="ar1 ar13 ac1 ac2 ac3">35.3%</TD><TD class="alignRight lightred" headers="ar1 ar13 ac1 ac2 ac4">36.2%</TD><TD class="alignRight lightred" headers="ar1 ar13 ac1 ac2 ac5">8.3%</TD><TD class="alignRight lightred" headers="ar1 ar13 ac1 ac2 ac6">55.5%</TD><TD class=alignRight headers="ar1 ar13 ac1 ac7">64.7%</TD><TD class=alignRight headers="ar1 ar13 ac8 ac9 ac10">87.7%</TD><TD class="alignRight lightred" headers="ar1 ar13 ac8 ac9 ac11">50.3%</TD><TD class="alignRight lightred" headers="ar1 ar13 ac8 ac9 ac12">1.9%</TD><TD class="alignRight lightred" headers="ar1 ar13 ac8 ac9 ac13">47.8%</TD><TD class=alignRight headers="ar1 ar13 ac8 ac14">12.3%</TD></TR></TBODY></TABLE>
<TABLE id=t2 class=widthFull border=1 cellSpacing=0 cellPadding=2><CAPTION class=alignCenter>Table 2. Weekly and cumulative numbers of positive influenza specimens by type, subtype and age-group reported through case-based laboratory reporting<SUP>3</SUP>, Canada, 2013-14</CAPTION><THEAD><TR class=bg-colour-yellow><TH id=br1 rowSpan=3>Age groups (years)</TH><TH id=bc1 colSpan=5>Weekly
(March 9 to March 15, 2014)</TH><TH id=bc8 colSpan=7>Cumulative
(August 25, 2013 to March 15, 2014)</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><TH id=bc15 colSpan=2 headers=bc8>Influenza A and B</TH></TR><TR class=bg-colour-grey-light><TH id=bc3 headers="bc1 bc2">A Total</TH><TH id=bc4 class="lightred " headers="bc1 bc2">A(H1) pdm09</TH><TH id=bc5 class="lightred " headers="bc1 bc2">A(H3)</TH><TH id=bc6 class="lightred " headers="bc1 bc2">A (UnS)</TH><TD class=alignCenter headers="bc1 bc7">Total</TD><TH id=bc10 headers="bc8 bc9">A Total</TH><TH id=bc11 class="lightred " headers="bc8 bc9">A(H1) pdm09</TH><TH id=bc12 class="lightred " headers="bc8 bc9">A(H3)</TH><TH id=bc13 class="lightred " headers="bc8 bc9">A (UnS)</TH><TD class=alignCenter headers="bc8 bc14">Total</TD><TH id=bc16 headers="bc8 bc15">#</TH><TH id=bc17 headers="bc8 bc15">%</TH></TR></THEAD><TFOOT><TR><TD class=fontSize85 colSpan=13><SUP id=footnote_t2_1>1 </SUP>Specimens from NT, YT, and NU are sent to reference laboratories in other provinces. Cumulative data includes updates to previous weeks.
<SUP id=footnote_t2_2>2 </SUP>Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
<SUP id=footnote_t2_3>3 </SUP>Table 2 includes specimens for which demographic information was reported. These represent a subset of all positive influenza cases reported.
UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.</TD></TR></TFOOT><TBODY><TR><TH id=br2 class=alignLeft headers=br1><5</TH><TD class=alignRight headers="br1 br2 bc1 bc2 bc3">36</TD><TD class=alignRight headers="br1 br2 bc1 bc2 bc4">6</TD><TD class=alignRight headers="br1 br2 bc1 bc2 bc5">5</TD><TD class=alignRight headers="br1 br2 bc1 bc2 bc6">25</TD><TD class=alignRight headers="br1 br2 bc1 bc7">30</TD><TD class=alignRight headers="br1 br2 bc8 bc9 bc10">3157</TD><TD class=alignRight headers="br1 br2 bc8 bc9 bc11">1404</TD><TD class=alignRight headers="br1 br2 bc8 bc9 bc12">31</TD><TD class=alignRight headers="br1 br2 bc8 bc9 bc13">1722</TD><TD class=alignRight headers="br1 br2 bc8 bc14">277</TD><TD class=alignRight headers="br1 br2 bc8 bc15 bc16">3434</TD><TD class=alignRight headers="br1 br2 bc8 bc15 bc17">18.1%</TD></TR><TR><TH id=br3 class=alignLeft headers=br1>5-19</TH><TD class=alignRight headers="br1 br3 bc1 bc2 bc3">13</TD><TD class=alignRight headers="br1 br3 bc1 bc2 bc4">3</TD><TD class=alignRight headers="br1 br3 bc1 bc2 bc5">1</TD><TD class=alignRight headers="br1 br3 bc1 bc2 bc6">9</TD><TD class=alignRight headers="br1 br3 bc1 bc7">43</TD><TD class=alignRight headers="br1 br3 bc8 bc9 bc10">1288</TD><TD class=alignRight headers="br1 br3 bc8 bc9 bc11">687</TD><TD class=alignRight headers="br1 br3 bc8 bc9 bc12">19</TD><TD class=alignRight headers="br1 br3 bc8 bc9 bc13">582</TD><TD class=alignRight headers="br1 br3 bc8 bc14">447</TD><TD class=alignRight headers="br1 br3 bc8 bc15 bc16">1735</TD><TD class=alignRight headers="br1 br3 bc8 bc15 bc17">9.1%</TD></TR><TR><TH id=br4 class=alignLeft headers=br1>20-44</TH><TD class=alignRight headers="br1 br4 bc1 bc2 bc3">39</TD><TD class=alignRight headers="br1 br4 bc1 bc2 bc4">17</TD><TD class=alignRight headers="br1 br4 bc1 bc2 bc5">1</TD><TD class=alignRight headers="br1 br4 bc1 bc2 bc6">21</TD><TD class=alignRight headers="br1 br4 bc1 bc7">45</TD><TD class=alignRight headers="br1 br4 bc8 bc9 bc10">4971</TD><TD class=alignRight headers="br1 br4 bc8 bc9 bc11">2751</TD><TD class=alignRight headers="br1 br4 bc8 bc9 bc12">40</TD><TD class=alignRight headers="br1 br4 bc8 bc9 bc13">2180</TD><TD class=alignRight headers="br1 br4 bc8 bc14">462</TD><TD class=alignRight headers="br1 br4 bc8 bc15 bc16">5433</TD><TD class=alignRight headers="br1 br4 bc8 bc15 bc17">28.7%</TD></TR><TR><TH id=br5 class=alignLeft headers=br1>45-64</TH><TD class=alignRight headers="br1 br5 bc1 bc2 bc3">49</TD><TD class=alignRight headers="br1 br5 bc1 bc2 bc4">10</TD><TD class=alignRight headers="br1 br5 bc1 bc2 bc5">1</TD><TD class=alignRight headers="br1 br5 bc1 bc2 bc6">38</TD><TD class=alignRight headers="br1 br5 bc1 bc7">78</TD><TD class=alignRight headers="br1 br5 bc8 bc9 bc10">4342</TD><TD class=alignRight headers="br1 br5 bc8 bc9 bc11">2339</TD><TD class=alignRight headers="br1 br5 bc8 bc9 bc12">45</TD><TD class=alignRight headers="br1 br5 bc8 bc9 bc13">1958</TD><TD class=alignRight headers="br1 br5 bc8 bc14">632</TD><TD class=alignRight headers="br1 br5 bc8 bc15 bc16">4974</TD><TD class=alignRight headers="br1 br5 bc8 bc15 bc17">26.2%</TD></TR><TR><TH id=br6 class=alignLeft headers=br1>65+</TH><TD class=alignRight headers="br1 br6 bc1 bc2 bc3">39</TD><TD class=alignRight headers="br1 br6 bc1 bc2 bc4">9</TD><TD class=alignRight headers="br1 br6 bc1 bc2 bc5">1</TD><TD class=alignRight headers="br1 br6 bc1 bc2 bc6">29</TD><TD class=alignRight headers="br1 br6 bc1 bc7">116</TD><TD class=alignRight headers="br1 br6 bc8 bc9 bc10">2402</TD><TD class=alignRight headers="br1 br6 bc8 bc9 bc11">975</TD><TD class=alignRight headers="br1 br6 bc8 bc9 bc12">102</TD><TD class=alignRight headers="br1 br6 bc8 bc9 bc13">1325</TD><TD class=alignRight headers="br1 br6 bc8 bc14">849</TD><TD class=alignRight headers="br1 br6 bc8 bc15 bc16">3251</TD><TD class=alignRight headers="br1 br6 bc8 bc15 bc17">17.1%</TD></TR><TR><TH id=br7 class=alignLeft headers=br1>Unknown</TH><TD class=alignRight headers="br1 br7 bc1 bc2 bc3">0</TD><TD class=alignRight headers="br1 br7 bc1 bc2 bc4">0</TD><TD class=alignRight headers="br1 br7 bc1 bc2 bc5">0</TD><TD class=alignRight headers="br1 br7 bc1 bc2 bc6">0</TD><TD class=alignRight headers="br1 br7 bc1 bc7">0</TD><TD class=alignRight headers="br1 br7 bc8 bc9 bc10">132</TD><TD class=alignRight headers="br1 br7 bc8 bc9 bc11">102</TD><TD class=alignRight headers="br1 br7 bc8 bc9 bc12">18</TD><TD class=alignRight headers="br1 br7 bc8 bc9 bc13">12</TD><TD class=alignRight headers="br1 br7 bc8 bc14">3</TD><TD class=alignRight headers="br1 br7 bc8 bc15 bc16">135</TD><TD class=alignRight headers="br1 br7 bc8 bc15 bc17">0.7%</TD></TR><TR><TH id=br8 class=alignLeft headers=br1>Total</TH><TD class=alignRight headers="br1 br8 bc1 bc2 bc3">176</TD><TD class="alignRight lightred" headers="br1 br8 bc1 bc2 bc4">45</TD><TD class="alignRight lightred" headers="br1 br8 bc1 bc2 bc5">9</TD><TD class="alignRight lightred" headers="br1 br8 bc1 bc2 bc6">122</TD><TD class=alignRight headers="br1 br8 bc1 bc7">312</TD><TD class=alignRight headers="br1 br8 bc8 bc9 bc10">16292</TD><TD class="alignRight lightred" headers="br1 br8 bc8 bc9 bc11">8258</TD><TD class="alignRight lightred" headers="br1 br8 bc8 bc9 bc12">255</TD><TD class="alignRight lightred" headers="br1 br8 bc8 bc9 bc13">7779</TD><TD class=alignRight headers="br1 br8 bc8 bc14">2670</TD><TD class=alignRight headers="br1 br8 bc8 bc15 bc16">18962</TD><TD class=alignRight headers="br1 br8 bc8 bc15 bc17">100.0%</TD></TR><TR><TH id=br9 class=alignLeft headers=br1>Percentage<SUP>2</SUP></TH><TD class=alignRight headers="br1 br9 bc1 bc2 bc3">36.1%</TD><TD class="alignRight lightred" headers="br1 br9 bc1 bc2 bc4">25.6%</TD><TD class="alignRight lightred" headers="br1 br9 bc1 bc2 bc5">5.1%</TD><TD class="alignRight lightred" headers="br1 br9 bc1 bc2 bc6">69.3%</TD><TD class=alignRight headers="br1 br9 bc1 bc7">63.9%</TD><TD class=alignRight headers="br1 br9 bc8 bc9 bc10">85.9%</TD><TD class="alignRight lightred" headers="br1 br9 bc8 bc9 bc11">50.7%</TD><TD class="alignRight lightred" headers="br1 br9 bc8 bc9 bc12">1.6%</TD><TD class="alignRight lightred" headers="br1 br9 bc8 bc9 bc13">47.7%</TD><TD class=alignRight headers="br1 br9 bc8 bc14">14.1%</TD><TD class=alignRight></TD><TD class=alignRight></TD></TR></TBODY></TABLE>
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Influenza Strain Characterizations
During the 2013-2014 influenza season, the National Microbiology Laboratory (NML) has antigenically characterized 1465 influenza viruses [67 A(H3N2), 1168 A(H1N1)pdm09 and 230 influenza B]. The vast majority (99%) of viruses were similar to the strains recommended by the WHO for the 2013-14 seasonal influenza vaccine. Two A(H1N1)pdm09 viruses showed reduced titres to antiserum against the reference A/California/07/2009 strain. Fifteen influenza B viruses were similar to the strain recommended by the WHO for the 2011-12 vaccine (Figure 4).
Figure 4. Influenza strain characterizations, Canada, 2013-14, N = 1465
The NML receives a proportion of the number of influenza positive specimens from provincial laboratories for strain characterization and antiviral resistance testing. Characterization data reflect the results of haemagglutination inhibition (HAI) testing compared to the reference influenza strains recommended by WHO
.The recommended components for the 2013-2014 northern hemisphere trivalent influenza vaccine include: an A/California/7/2009 (H1N1)pdm09-like virus, an A(H3N2) virus antigenically like the cell-propagated prototype virus A/Victoria/361/2011b (e.g. A/Texas/50/2012), and a B/Massachusetts/2/2012-like virus (Yamagata lineage).
Text equivalent for figure 4Influenza strain characterizations, Canada, 2013-2014, N =3
Antiviral Resistance
During the 2013-2014 influenza season, NML has tested 1098 influenza viruses for resistance to oseltamivir and all but two were sensitive. All 1102 viruses tested for resistance to zanamivir were sensitive. All 1264 influenza A viruses tested for amantadine resistance 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, 2013-2014</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 class=fontSize85 colSpan=7><SUP>*</SUP> NA - not applicable</TD></TR></TFOOT><TBODY><TR><TH id=cr2 class="alignLeft lightred" headers=cr1>A (H3N2)</TH><TD class=alignRight headers="cr1 cr2 cc1 cc2">55</TD><TD class=alignRight headers="cr1 cr2 cc1 cc3">0</TD><TD class=alignRight headers="cr1 cr2 cc4 cc5">55</TD><TD class=alignRight headers="cr1 cr2 cc4 cc6">0</TD><TD class=alignRight headers="cr1 cr2 cc7 cc8">91</TD><TD class=alignRight headers="cr1 cr2 cc7 cc9">91 (100%)</TD></TR><TR><TH id=cr3 class="alignLeft lightred" headers=cr1>A (H1N1)</TH><TD class=alignRight headers="cr1 cr3 cc1 cc2">913</TD><TD class=alignRight headers="cr1 cr3 cc1 cc3">2 (0.2%)</TD><TD class=alignRight headers="cr1 cr3 cc4 cc5">918</TD><TD class=alignRight headers="cr1 cr3 cc4 cc6">0</TD><TD class=alignRight headers="cr1 cr3 cc7 cc8">1173</TD><TD class=alignRight headers="cr1 cr3 cc7 cc9">1173 (100%)</TD></TR><TR><TH id=cr4 class="alignLeft lightred" headers=cr1>B</TH><TD class=alignRight headers="cr1 cr4 cc1 cc2">130</TD><TD class=alignRight headers="cr1 cr4 cc1 cc3">0</TD><TD class=alignRight headers="cr1 cr4 cc4 cc5">129</TD><TD class=alignRight headers="cr1 cr4 cc4 cc6">0</TD><TD class=alignRight headers="cr1 cr4 cc7 cc8">NA <SUP>*</SUP></TD><TD class=alignRight headers="cr1 cr4 cc7 cc9">NA <SUP>*</SUP></TD></TR><TR><TH id=cr5 class="alignLeft lightred" headers=cr1>TOTAL</TH><TD class=alignRight headers="cr1 cr5 cc1 cc2">1098</TD><TD class=alignRight headers="cr1 cr5 cc1 cc3">2 (0.2%)</TD><TD class=alignRight headers="cr1 cr5 cc4 cc5">1102</TD><TD class=alignRight headers="cr1 cr5 cc4 cc6">0</TD><TD class=alignRight headers="cr1 cr5 cc7 cc8">1264</TD><TD class=alignRight headers="cr1 cr5 cc7 cc9">1264 (100%)</TD></TR></TBODY></TABLE>
Influenza-like Illness (ILI) Consultation Rate
The national influenza-like-illness (ILI) consultation rate decreased from 36.9/1,000 in week 10 to 31.2/1,000 in week 11; and was below the expected range for week 11 (Figure 5).
Figure 5. Influenza-like-illness (ILI) consultation rates by report week, compared to the 1996-97 through to 2012-13 seasons (with pandemic data suppressed), Canada, 2013-2014
Note: No data available for mean rate for weeks 19 to 39 for the 1996-1997 through 2002-2003 seasons. Delays in the reporting of data may cause data to change retrospectively. The calculation of the average ILI consultation rate over 17 seasons was aligned with influenza activity in each season. In BC, AB, and SK, data is compiled by a provincial sentinel surveillance program for reporting to FluWatch. The number of sentinel physicians in each province or territory is as follows: BC(21), AB(80), SK(11), MB(18), ON(169), QC(14), NB(29), NS(26), PE(4), NL(16), NU(1), NT(14), YT(13). Not all sentinel physicians report every week.
Text equivalent for figure 5Influenza-like-illness (ILI) consultation rates by report week, compared to the 1996-97 through to 2012-13 seasons (with pandemic data suppressed), Canada, 2013-2014
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Influenza Outbreak Surveillance
In week 11, nine new influenza outbreaks were reported: eight in long-term care facilities (LTCF) and one in a hospital (Figure 6). In addition, one outbreak of influenza-like-illness was reported in a school. Among the seven LTCF outbreaks with available data, three were reported to be due to influenza B.
Figure 6. Overall number of new influenza outbreaks by report week, Canada, 2013-2014
1 All provinces and territories except NU report outbreaks in long-term care facilities. All provinces and territories with the exception of NU and QC report outbreaks in hospitals. Outbreaks of influenza or influenza-like-illness in other facilities are reported to FluWatch but reporting varies between jurisdictions. Outbreak definitions are included at the end of the report.
Text equivalent for figure 6Overall number of new influenza outbreaks by report week, Canada, 2013-2014
Pharmacy Surveillance
In week 11, the overall proportion of prescriptions for influenza antivirals increased slightly, based on increases in all age-groups except children 2-18 years of age. The proportion of prescriptions for infants (<2 years of age) increased for the second week in a row, however, the number of prescriptions in this age-group is small. Overall this season, the largest proportion of prescriptions for antivirals has been among children 2-18 years of age and adults 19-64 years of age, in keeping with laboratory detections of influenza (Figure 7).
Figure 7. Proportion of prescription sales for influenza antivirals by age-group and week, Canada, 2013-14
Note: Pharmacy sales data are provided to the Public Health Agency of Canada by Rx Canada Inc. and sourced from major retail drug chains representing over 3,000 stores nationwide (excluding Nunavut) in 85% of Health Regions. Data provided include the number of new antiviral prescriptions (for Tamiflu and Relenza) and the total number of new prescriptions dispensed by Province/Territory and age group. Age-groups: Infant: 0-2y, Child: 2-18y; Adult: 19-64y, Senior: ≥65y.
Text equivalent for figure 7Proportion of prescription sales for influenza antivirals by age-group and week, Canada, 2013-14
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Sentinel Hospital Influenza Surveillance
Paediatric Influenza Hospitalizations and Deaths (IMPACT)
In week 11, 22 new laboratory-confirmed influenza-associated paediatric (≤16 years of age) hospitalizations were reported by the Immunization Monitoring Program Active (IMPACT) network, compared to 38 in week 10. In keeping with the increased circulation of influenza B, influenza B was reported in 12 of the 22 cases in week 11 (Figure 8a). Although the number of cases is small, a greater proportion of cases with influenza B this season have been children between 2 and 10 years of age compared to A(H1N1)pdm09. In week 11, one ICU admission was reported in a child 6-23 months of age with influenza A(unsubtyped). No deaths were reported in week 11.
To date this season, a total of 613 influenza-associated paediatric hospitalizations have been reported by the IMPACT network, 88% of which have been influenza A, and almost all of those subtyped (97%) were A(H1N1)pdm09. Children <5 years of age represent 74% of cases to date (Table 4). Eighty-six ICU admissions have been reported, of which 58 (67%) were children <5 years of age (Figure 9a). All but five were cases with influenza A, and 96% of those subtyped were A(H1N1)pdm09. Among the 79 ICU cases with available data, 51 (65%) were reported to have underlying medical conditions. No deaths have been reported.
Note: The number of hospitalizations reported through IMPACT represents a subset of all influenza-associated paediatric hospitalizations in Canada. Delays in the reporting of data may cause data to change retrospectively.
Adult Influenza Hospitalizations and Deaths (PCIRN)
In week 11, 32 new laboratory-confirmed influenza-associated adult (≥16 years of age) hospitalizations were reported through active surveillance by the PHAC/CIHR Influenza Research Network (PCIRN) Serious Outcomes Surveillance (SOS) network, compared to 55 in week 10. In week 11, there continued to be more hospitalizations associated with influenza B than influenza A (Figure 8b). All but seven hospitalizations occurred among adults ≥45 years of age. No ICU admissions or deaths were reported in week 11.
To date this season, 1250 influenza-associated hospitalizations have been reported by the PCIRN-SOS network, 1105 (88.4%) with influenza A, predominantly A(H1N1)pdm09 (Table 5). ICU admission was required for 209 hospitalizations, all but eight of which were cases with influenza A (112 A(H1N1)pdm09, five A(H3N2) and 84 A(unsubtyped)). More than three quarters of hospitalizations and approximately 80% of ICU admissions were ≥45 years of age. Of the 168 ICU admissions with available information, 148 (88.1%) were reported to have at least one comorbidity and of the 180 ICU admissions with available information 131 (72.8%) reported not having been vaccinated this season. Fifty-eight deaths have been reported, all but four with influenza A (32 A(H1N1)pdm09, two A(H3N2) and 20 A(unsubtyped)); six cases 20-44 years of age, 27 cases 45-64 years of age and 25 cases ≥65 years of age (Figure 9b).
Note: PCIRN-SOS conducted passive surveillance from April 30th to November 14th, 2013. Cases reported during this period were identified by laboratory detection of influenza among patients admitted to participating hospitals. Active surveillance began November 15th during which time PCIRN site coordinators investigate cases potentially related to influenza. Data from both active and passive surveillance reported during the 2013-14 season are included in this report. The number of hospitalizations reported through PCIRN represents a subset of all influenza-associated adult hospitalizations in Canada. Delays in the reporting of data may cause data to change retrospectively.
<TABLE class=widthFull border=1 cellSpacing=0 cellPadding=2><CAPTION id=t4 class=alignCenter>Table 4 - Cumulative numbers of paediatric hospitalizations with influenza reported by the IMPACT network, Canada, 2013-14</CAPTION><THEAD><TR class=bg-colour-yellow><TH id=dr1 rowSpan=3>Age groups </TH><TH id=dc1 colSpan=6>Cumulative (Aug. 25, 2013 to March 15, 2014) </TH></TR><TR class=bg-colour-yellow><TH id=dc2 colSpan=4 headers=dc1>Influenza A </TH><TH id=dc7 headers=dc1>B </TH><TH id=dc8 headers=dc1>Influenza A and B </TH></TR><TR class=bg-colour-grey-light><TH id=dc3 headers="dc1 dc2">A Total </TH><TH id=dc4 class="lightred " headers="dc1 dc2">A(H1) pdm09 </TH><TH id=dc5 class="lightred " headers="dc1 dc2">A(H3) </TH><TH id=dc6 class="lightred " headers="dc1 dc2">A (UnS) </TH><TD class=alignCenter headers="dc1 dc7">Total</TD><TD class=alignCenter headers="dc1 dc8"># (%)</TD></TR></THEAD><TFOOT><TR><TD class=fontSize85 colSpan=7><SUP id=footnote_t4_1>1</SUP> Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.</TD></TR></TFOOT><TBODY><TR><TH id=dr2 class=alignLeft headers=dr1>0-5m </TH><TD class=alignRight headers="dr1 dr2 dc1 dc2 dc3">102</TD><TD class=alignRight headers="dr1 dr2 dc1 dc2 dc4">33</TD><TD class=alignRight headers="dr1 dr2 dc1 dc2 dc5">0</TD><TD class=alignRight headers="dr1 dr2 dc1 dc2 dc6">69</TD><TD class=alignRight headers="dr1 dr2 dc1 dc7">3</TD><TD class=alignRight headers="dr1 dr2 dc1 dc8">105 (17%)</TD></TR><TR><TH id=dr3 class=alignLeft headers=dr1>6-23m </TH><TD class=alignRight headers="dr1 dr3 dc1 dc2 dc3">157</TD><TD class=alignRight headers="dr1 dr3 dc1 dc2 dc4">45</TD><TD class=alignRight headers="dr1 dr3 dc1 dc2 dc5">1</TD><TD class=alignRight headers="dr1 dr3 dc1 dc2 dc6">111</TD><TD class=alignRight headers="dr1 dr3 dc1 dc7">9</TD><TD class=alignRight headers="dr1 dr3 dc1 dc8">166 (27%)</TD></TR><TR><TH id=dr4 class=alignLeft headers=dr1>2-4y </TH><TD class=alignRight headers="dr1 dr4 dc1 dc2 dc3">159</TD><TD class=alignRight headers="dr1 dr4 dc1 dc2 dc4">53</TD><TD class=alignRight headers="dr1 dr4 dc1 dc2 dc5">3</TD><TD class=alignRight headers="dr1 dr4 dc1 dc2 dc6">103</TD><TD class=alignRight headers="dr1 dr4 dc1 dc7">24</TD><TD class=alignRight headers="dr1 dr4 dc1 dc8">183 (30%)</TD></TR><TR><TH id=dr5 class=alignLeft headers=dr1>5-9y </TH><TD class=alignRight headers="dr1 dr5 dc1 dc2 dc3">81</TD><TD class=alignRight headers="dr1 dr5 dc1 dc2 dc4">25</TD><TD class=alignRight headers="dr1 dr5 dc1 dc2 dc5">0</TD><TD class=alignRight headers="dr1 dr5 dc1 dc2 dc6">56</TD><TD class=alignRight headers="dr1 dr5 dc1 dc7">30</TD><TD class=alignRight headers="dr1 dr5 dc1 dc8">111 (18%)</TD></TR><TR><TH id=dr6 class=alignLeft headers=dr1>10-16y </TH><TD class=alignRight headers="dr1 dr6 dc1 dc2 dc3">41</TD><TD class=alignRight headers="dr1 dr6 dc1 dc2 dc4">15</TD><TD class=alignRight headers="dr1 dr6 dc1 dc2 dc5">1</TD><TD class=alignRight headers="dr1 dr6 dc1 dc2 dc6">25</TD><TD class=alignRight headers="dr1 dr6 dc1 dc7">7</TD><TD class=alignRight headers="dr1 dr6 dc1 dc8">48 (8%)</TD></TR><TR><TH id=dr7 class=alignLeft headers=dr1>Total </TH><TD class=alignRight headers="dr1 dr7 dc1 dc2 dc3">540</TD><TD class="alignRight lightred" headers="dr1 dr7 dc1 dc2 dc4">171</TD><TD class="alignRight lightred" headers="dr1 dr7 dc1 dc2 dc5">5</TD><TD class="alignRight lightred" headers="dr1 dr7 dc1 dc2 dc6">364</TD><TD class=alignRight headers="dr1 dr7 dc1 dc7">73</TD><TD class=alignRight headers="dr1 dr7 dc1 dc8">613</TD></TR><TR><TH id=dr8 class=alignLeft headers=dr1>% <SUP>1</SUP> </TH><TD class=alignRight headers="dr1 dr8 dc1 dc2 dc3">88.1%</TD><TD class="alignRight lightred" headers="dr1 dr8 dc1 dc2 dc4">31.7%</TD><TD class="alignRight lightred" headers="dr1 dr8 dc1 dc2 dc5">0.9%</TD><TD class="alignRight lightred" headers="dr1 dr8 dc1 dc2 dc6">67.4%</TD><TD class=alignRight headers="dr1 dr8 dc1 dc7">11.9%</TD><TD class=alignRight headers="dr1 dr8 dc1 dc8">100.0%</TD></TR></TBODY></TABLE>
<TABLE class=widthFull border=1 cellSpacing=0 cellPadding=2><CAPTION class=alignCenter>Table 5 - Cumulative numbers of adult hospitalizations with influenza
reported by the PCIRN-SOS network, Canada, 2013-14</CAPTION><THEAD><TR class=bg-colour-yellow><TH id=er1 rowSpan=3>Age groups </TH><TH id=ec1 class=noWrap colSpan=6>Cumulative (Aug. 25, 2013 to March 15, 2014)<SUP>*</SUP></TH></TR><TR class=bg-colour-yellow><TH id=ec2 colSpan=4 headers=ec1>Influenza A </TH><TH id=ec7 headers=ec1>B </TH><TH id=ec8 headers=ec1>Influenza A and B </TH></TR><TR class=bg-colour-grey-light><TH id=ec3 headers="ec1 ec2">A Total </TH><TH id=ec4 class="lightred " headers="ec1 ec2">A(H1) pdm09 </TH><TH id=ec5 class="lightred " headers="ec1 ec2">A(H3) </TH><TH id=ec6 class="lightred " headers="ec1 ec2">A(UnS) </TH><TD class=alignCenter headers="ec1 ec7">Total</TD><TD class=alignCenter headers="ec1 ec8"># (%)</TD></TR></THEAD><TFOOT><TR><TD class=fontSize85 colSpan=7><SUP id=footnote_t5_1>1</SUP> Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.
<SUP id=t5_star>*</SUP> One case for which the influenza type has not yet been reported, and three cases for which the age-group was not reported, are not included in Table 5.</TD></TR></TFOOT><TBODY><TR><TH id=er2 class=alignLeft headers=er1>16-20 </TH><TD class=alignRight headers="er1 er2 ec1 ec2 ec3">13</TD><TD class=alignRight headers="er1 er2 ec1 ec2 ec4">3</TD><TD class=alignRight headers="er1 er2 ec1 ec2 ec5">0</TD><TD class=alignRight headers="er1 er2 ec1 ec2 ec6">10</TD><TD class=alignRight headers="er1 er2 ec1 ec7">1</TD><TD class=alignRight headers="er1 er2 ec1 ec8">14 (1%)</TD></TR><TR><TH id=er3 class=alignLeft headers=er1>20-44 </TH><TD class=alignRight headers="er1 er3 ec1 ec2 ec3">241</TD><TD class=alignRight headers="er1 er3 ec1 ec2 ec4">127</TD><TD class=alignRight headers="er1 er3 ec1 ec2 ec5">4</TD><TD class=alignRight headers="er1 er3 ec1 ec2 ec6">110</TD><TD class=alignRight headers="er1 er3 ec1 ec7">10</TD><TD class=alignRight headers="er1 er3 ec1 ec8">251 (20%)</TD></TR><TR><TH id=er4 class=alignLeft headers=er1>45-64 </TH><TD class=alignRight headers="er1 er4 ec1 ec2 ec3">433</TD><TD class=alignRight headers="er1 er4 ec1 ec2 ec4">201</TD><TD class=alignRight headers="er1 er4 ec1 ec2 ec5">5</TD><TD class=alignRight headers="er1 er4 ec1 ec2 ec6">227</TD><TD class=alignRight headers="er1 er4 ec1 ec7">35</TD><TD class=alignRight headers="er1 er4 ec1 ec8">468 (38%)</TD></TR><TR><TH id=er5 class=alignLeft headers=er1>65+ </TH><TD class=alignRight headers="er1 er5 ec1 ec2 ec3">415</TD><TD class=alignRight headers="er1 er5 ec1 ec2 ec4">201</TD><TD class=alignRight headers="er1 er5 ec1 ec2 ec5">32</TD><TD class=alignRight headers="er1 er5 ec1 ec2 ec6">182</TD><TD class=alignRight headers="er1 er5 ec1 ec7">98</TD><TD class=alignRight headers="er1 er5 ec1 ec8">513 (41%)</TD></TR><TR><TH id=er6 class=alignLeft headers=er1>Total </TH><TD class=alignRight headers="er1 er6 ec1 ec2 ec3">1102</TD><TD class="alignRight lightred" headers="er1 er6 ec1 ec2 ec4">532</TD><TD class="alignRight lightred" headers="er1 er6 ec1 ec2 ec5">41</TD><TD class="alignRight lightred" headers="er1 er6 ec1 ec2 ec6">529</TD><TD class=alignRight headers="er1 er6 ec1 ec7">144</TD><TD class=alignRight headers="er1 er6 ec1 ec8">1246</TD></TR><TR><TH id=er7 class=alignLeft headers=er1>%<SUP>1</SUP></TH><TD class=alignRight headers="er1 er7 ec1 ec2 ec3">88%</TD><TD class="alignRight lightred" headers="er1 er7 ec1 ec2 ec4">48%</TD><TD class="alignRight lightred" headers="er1 er7 ec1 ec2 ec5">4%</TD><TD class="alignRight lightred" headers="er1 er7 ec1 ec2 ec6">48%</TD><TD class=alignRight headers="er1 er7 ec1 ec7">12%</TD><TD class=alignRight headers="er1 er7 ec1 ec8">100%</TD></TR></TBODY></TABLE>
Figure 8. Number of cases of influenza reported by sentinel hospital networks, by week, Canada, 2013-14
A) Paediatric hospitalizations (≤16 years of age, IMPACT)
Text equivalent for figure 8aNumber of cases of influenza reported by sentinel hospital networks, by week, Canada, 2013-14: Paediatric hospitalizations (≤16 years of age, IMPACT)
B) Adult hospitalizations (≥16 year of age, PCIRN-SOS)
* See footnote above following the section related to PCIRN-SOS data.
Text equivalent for figure 8bNumber of cases of influenza reported by sentinel hospital networks, by week, Canada, 2013-14: Adult hospitalizations (>16 year of age, PCIRN-SOS)
Figure 9. Percentage of hospitalizations, ICU admissions and deaths with influenza reported by age-group, Canada, 2013-14
A) Paediatric hospitalizations (≤16 years of age, IMPACT)
Text equivalent for figure 9aPercentage of hospitalizations, ICU admissions and deaths with influenza reported by age-group, Canada, 2013-14: Paediatric hospitalizations (≤16 years of age, IMPACT)
B) Adult hospitalizations (≥16 year of age, PCIRN-SOS)
Text equivalent for figure 9bPercentage of hospitalizations, ICU admissions and deaths with influenza reported by age-group, Canada, 2013-14: Adult hospitalizations (≥16 year of age, PCIRN-SOS)
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Provincial/Territorial Influenza Hospitalizations and Deaths
In week 11, 94 laboratory-confirmed influenza-associated hospitalizations were reported from participating provinces and territories.* As with other surveillance indicators in week 11, the majority were cases of influenza B (52, 55.3%). Among the five ICU admissions reported in week 11, three were adults 45-64 years of age. One death was reported in week 11, an adult ≥65 years of age with influenza B. The number of new influenza-associated hospitalizations and deaths reported for the current week may include cases from Ontario that occurred in previous weeks, as a result of retrospective updates to the cumulative total.
To date this season, 3,570 influenza-associated hospitalizations have been reported, 93.2% with influenza A. The majority (57.4%) of hospitalizations have been cases 45 years of age of older. A significantly greater proportion of cases of influenza B have been ≥65 years of age compared to cases of A(H1N1)pdm09 this season (Table 6). A total of 324 ICU admissions have been reported this season, of which 66.6% were among adults 20-64 years of age. A total of 197 deaths have been reported. The highest proportion of deaths has been among adults 20-64 years of age (49.7%), followed by adults ≥65 years of age (40.6%). In keeping with the late-season circulation, influenza B has been increasingly reported among severe cases of influenza. To date this season, influenza B has been reported in 6.8% of hospitalizations, 1.5% of ICU admissions, and 5.6 % of deaths. It is important to note that the hospitalization or death does not have to be attributable to influenza, a positive laboratory test is sufficient for reporting. Detailed clinical information (e.g. underlying medical conditions) is not known for these cases.
* Note: Influenza-associated hospitalizations are not reported to PHAC by the following Provinces and Territory: BC, NU, QC, NS, and NB. Only hospitalizations that require intensive medical care are reported by Saskatchewan. ICU admissions are not distinguished among hospital admissions reported from Ontario. Data may also include cases reported by the IMPACT and PCIRN networks.
<TABLE class=widthFull border=1 cellSpacing=0 cellPadding=2><CAPTION id=t6 class=alignCenter>Table 6. Cumulative number of hospitalizations with influenza reported by the participating provinces and territories, Canada, 2013-14</CAPTION><THEAD><TR class=bg-colour-yellow><TH id=fr1 rowSpan=3>Age groups </TH><TH id=fc1 colSpan=6>Cumulative (Aug. 25, 2013 to March 15, 2014)</TH></TR><TR class=bg-colour-yellow><TH id=fc2 colSpan=4 headers=fc1>Influenza A</TH><TH id=fc7 headers=fc1>B</TH><TH id=fc8 headers=fc1>Influenza A and B</TH></TR><TR class=bg-colour-grey-light><TH id=fc3 headers="fc1 fc2">A Total</TH><TH id=fc4 class=lightred headers="fc1 fc2">A(H1) pdm09</TH><TH id=fc5 class=lightred headers="fc1 fc2">A(H3)</TH><TH id=fc6 class=lightred headers="fc1 fc2">A (UnS)</TH><TD class=alignCenter headers="fc1 fc7">Total</TD><TD class=alignCenter headers="fc1 fc8"># (%)</TD></TR></THEAD><TFOOT><TR><TD class=fontSize85 colSpan=8><SUP id=footnote_t6_1>1</SUP> Percentage of tests positive for sub-types of influenza A are a percentage of all influenza A detections.
UnS: unsubtyped: The specimen was typed as influenza A, but no result for subtyping was available.</TD></TR></TFOOT><TBODY><TR><TH id=fr2 class=alignLeft headers=fr1>0-4 years</TH><TD class=alignRight headers="fr1 fr2 fc1 fc2 fc3">568</TD><TD class=alignRight headers="fr1 fr2 fc1 fc2 fc4">275</TD><TD class=alignRight headers="fr1 fr2 fc1 fc2 fc5">6</TD><TD class=alignRight headers="fr1 fr2 fc1 fc2 fc6">287</TD><TD class=alignRight headers="fr1 fr2 fc1 fc7">36</TD><TD class=alignRight headers="fr1 fr2 fc1 fc8">604 (17%)</TD></TR><TR><TH id=fr3 class=alignLeft headers=fr1>5-14 years</TH><TD class=alignRight headers="fr1 fr3 fc1 fc2 fc3">125</TD><TD class=alignRight headers="fr1 fr3 fc1 fc2 fc4">64</TD><TD class=alignRight headers="fr1 fr3 fc1 fc2 fc5">6</TD><TD class=alignRight headers="fr1 fr3 fc1 fc2 fc6">55</TD><TD class=alignRight headers="fr1 fr3 fc1 fc7">35</TD><TD class=alignRight headers="fr1 fr3 fc1 fc8">160 (4%)</TD></TR><TR><TH id=fr4 class=alignLeft headers=fr1>15-19 years</TH><TD class=alignRight headers="fr1 fr4 fc1 fc2 fc3">34</TD><TD class=alignRight headers="fr1 fr4 fc1 fc2 fc4">19</TD><TD class=alignRight headers="fr1 fr4 fc1 fc2 fc5">3</TD><TD class=alignRight headers="fr1 fr4 fc1 fc2 fc6">12</TD><TD class=alignRight headers="fr1 fr4 fc1 fc7">1</TD><TD class=alignRight headers="fr1 fr4 fc1 fc8">35 (1%)</TD></TR><TR><TH id=fr5 class=alignLeft headers=fr1>20-44 years </TH><TD class=alignRight headers="fr1 fr5 fc1 fc2 fc3">577</TD><TD class=alignRight headers="fr1 fr5 fc1 fc2 fc4">408</TD><TD class=alignRight headers="fr1 fr5 fc1 fc2 fc5">4</TD><TD class=alignRight headers="fr1 fr5 fc1 fc2 fc6">165</TD><TD class=alignRight headers="fr1 fr5 fc1 fc7">15</TD><TD class=alignRight headers="fr1 fr5 fc1 fc8">592 (17%)</TD></TR><TR><TH id=fr6 class=alignLeft headers=fr1>45-64 years </TH><TD class=alignRight headers="fr1 fr6 fc1 fc2 fc3">1052</TD><TD class=alignRight headers="fr1 fr6 fc1 fc2 fc4">675</TD><TD class=alignRight headers="fr1 fr6 fc1 fc2 fc5">21</TD><TD class=alignRight headers="fr1 fr6 fc1 fc2 fc6">356</TD><TD class=alignRight headers="fr1 fr6 fc1 fc7">52</TD><TD class=alignRight headers="fr1 fr6 fc1 fc8">1104 (31%)</TD></TR><TR><TH id=fr7 class=alignLeft headers=fr1>65+ years </TH><TD class=alignRight headers="fr1 fr7 fc1 fc2 fc3">844</TD><TD class=alignRight headers="fr1 fr7 fc1 fc2 fc4">448</TD><TD class=alignRight headers="fr1 fr7 fc1 fc2 fc5">63</TD><TD class=alignRight headers="fr1 fr7 fc1 fc2 fc6">333</TD><TD class=alignRight headers="fr1 fr7 fc1 fc7">100</TD><TD class=alignRight headers="fr1 fr7 fc1 fc8">944 (26%)</TD></TR><TR><TH id=fr10 class=alignLeft headers=fr1>Unknown</TH><TD class=alignRight headers="fc1 fc2 fc3">127</TD><TD class=alignRight headers="fc1 fc2 fc4">92</TD><TD class=alignRight headers="fc1 fc2 fc5">3</TD><TD class=alignRight headers="fc1 fc2 fc6">29</TD><TD class=alignRight headers="fc1 fc7">4</TD><TD class=alignRight headers="fc1 fc8">128 (4%)</TD></TR><TR><TH id=fr8 class=alignLeft headers=fr1>Total </TH><TD class=alignRight headers="fr1 fr8 fc1 fc2 fc3">3327</TD><TD class="alignRight lightred" headers="fr1 fr8 fc1 fc2 fc4">1981</TD><TD class="alignRight lightred" headers="fr1 fr8 fc1 fc2 fc5">106</TD><TD class="alignRight lightred" headers="fr1 fr8 fc1 fc2 fc6">1237</TD><TD class=alignRight headers="fr1 fr8 fc1 fc7">243</TD><TD class=alignRight headers="fr1 fr8 fc1 fc8">3567</TD></TR><TR><TH id=fr9 class=alignLeft headers=fr1>Percentage <SUP>1</SUP> </TH><TD class=alignRight headers="fr1 fr9 fc1 fc2 fc3">93.3%</TD><TD class="alignRight lightred" headers="fr1 fr9 fc1 fc2 fc4">59.5%</TD><TD class="alignRight lightred" headers="fr1 fr9 fc1 fc2 fc5">3.2%</TD><TD class="alignRight lightred" headers="fr1 fr9 fc1 fc2 fc6">37.2%</TD><TD class=alignRight headers="fr1 fr9 fc1 fc7">6.8%</TD><TD class=alignRight headers="fr1 fr9 fc1 fc8">100%</TD></TR></TBODY></TABLE>
See additional data on Reported Influenza Hospitalizations and Deaths in Canada: 2009-10 to 2013-14 on the Public Health Agency of Canada website.
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