Re: Ontario Influenza Bulletin 2011-2012 - Surveillance Week 7
Re: Ontario Influenza Bulletin 2011-2012 - Surveillance Week 7
Ontario Influenza Bulletin I 2011-2012
SURVEILLANCE WEEK 7 (February 12, 2012 ? February 18, 2012)
Ontario Influenza Bulletin, 2011-2012 (September 1, 2011 ? February 18, 2012)
Produced by: Surveillance and Epidemiology, Public Health Ontario
Summary of current and season to date influenza activity
Year-to-date influenza activity for the 2011-2012 season has been lower than the same period in previous years:
o A total of 502 influenza cases have been reported for the 2011-2012 surveillance season to date, of which 144 were reported during week 7.
o While the number of influenza cases reported by public health units have increased, percent positivity for influenza in week 7 is similar to week 6.
o The majority of influenza cases reported for the 2011-2012 season to date were subtyped as influenza A(H1N1)pdm09 (93 cases) or influenza B (283 cases), which together account for 74.9% (376/502) of cases this season.
o The majority of influenza cases this season have been children under 5 years old (162 cases) and adults 65 years of age and older (94 cases), which together account for 51.0% (256/502) of cases reported to date.
The highest number of cases (112) has occurred in the 1 to 4 year old age group, which represents 22.3% of cases.
o Among influenza cases that have been hospitalized, 36.4% (52/143) were children under 5 years old and 25.2% (36/143) were in adults over the age of 65 (Table 2).
o Compared to the same period in the 2010-2011 season, fewer influenza cases and outbreaks have been reported this season from September 1, 2011 to February 18, 2012.
The cause(s) of ILI in Ontario from September 1, 2011 to February 18, 2012 has changed as the season progressed:
o Since week 5, influenza B has been the dominant circulating influenza virus. Of the 128 influenza B isolates that have been characterized at the National Microbiology Laboratory, 72 (56.3%) are a different strain (B/Wisconsin/01/2010-like) and lineage than is contained in this season?s trivalent influenza vaccine. Note that the World Health Organization has recommended that this strain be included in the vaccine for the 2012-2013 influenza season for the Northern Hemisphere.
o Since week 1, 11 institutional influenza outbreaks have been reported: three influenza A, seven influenza B, and one combined A and B outbreak. Since week 1, coronavirus has been the most common virus identified in institutional respiratory outbreaks.
o RSV had the highest percent positivity among laboratory tests of respiratory samples during week 7 at 16.08% (Table 3). RSV also has had the highest percent positivity among isolates submitted for testing for the season to date at 12.61%.
o Coronavirus has had a percent positivity above 5% each week since week 52. For week 7, coronavirus had a percent positivity of 11.38%.
o The percent positivity for human metapneumovirus increased from 2.13% in week 6 to 7.67% in week 7.
...
<TABLE dir=ltr border=1 cellSpacing=0 cellPadding=7 width=550><TBODY><TR><TD height=16 vAlign=top width="20%">
Table 2. [FONT=Calibri,Calibri][FONT=Calibri,Calibri]Number of hospitalizations and deaths among influenza cases during week 7 and cumulative (in brackets) for the season by age group since September 1, 2011 [/FONT][/FONT]Age Group
</TD><TD height=16 vAlign=top width="20%">
Number of Hospitalizations
</TD><TD height=16 vAlign=top width="20%">
Cumulative Rate per 100,000
</TD><TD height=16 vAlign=top width="20%">
Number of Deaths
</TD><TD height=16 vAlign=top width="20%">
Cumulative Rate per 100,000
</TD></TR><TR><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
<1 [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
6 (18) [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
12.71 [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
0 (0) [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
0.00 [/FONT][/FONT]
</TD></TR><TR><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
1-4 [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
7 (34) [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
5.96 [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
0 (1) [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
0.18 [/FONT][/FONT]
</TD></TR><TR><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
5-14 [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
6 (16) [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
1.07 [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
0 (0) [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
0.00 [/FONT][/FONT]
</TD></TR><TR><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
15-24 [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
1 (3) [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
0.17 [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
0 (0) [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
0.00 [/FONT][/FONT]
</TD></TR><TR><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
25-44 [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
2 (16) [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
0.44 [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
0 (0) [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
0.00 [/FONT][/FONT]
</TD></TR><TR><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
45-64 [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
2 (20) [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
0.54 [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
0 (0) [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
0.00 [/FONT][/FONT]
</TD></TR><TR><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
65+ [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
10 (36) [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
1.96 [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
0 (4) [/FONT][/FONT]
</TD><TD height=7 vAlign=top width="20%">[FONT=Calibri,Calibri][FONT=Calibri,Calibri]
0.22 [/FONT][/FONT]
</TD></TR><TR><TD height=7 vAlign=top width="20%">
Total
</TD><TD height=7 vAlign=top width="20%">
34 (143)
</TD><TD height=7 vAlign=top width="20%">
1.08
</TD><TD height=7 vAlign=top width="20%">
0 (5)
</TD><TD height=7 vAlign=top width="20%">
0.04
</TD></TR></TBODY></TABLE>
...
Full report:
http://www.oahpp.ca/resources/documents/flubulletin/Influenza Bulletin-Week 7.pdf