Announcement

**Pathfinder** · November 25, 2011, 07:13 PM

Re: Ontario Influenza Bulletin 2011-2012 - Surveillance Week 46

Ontario Influenza Bulletin I 2011-2012
SURVEILLANCE WEEK 46 (November 13, 2011 ? November 19, 2011)

Produced by: Surveillance and Epidemiology Program,
Public Health Ontario

Summary of current and season to date influenza activity

? There has been little to no influenza activity for the 2011-2012 season to date

o Three cases of influenza A/H3 have been reported as of November 19, 2011 (end of week 46). The cases have been from three different health units: Ottawa, Toronto, and Thunder Bay (Table 1). One influenza B case was reported in Toronto as of Nov 19, 2011.

o Two additional cases of influenza A have been identified in Middlesex-London and Toronto and will be reflected in next week?s bulletin.

o Compared to the 2010-2011 season, there were fewer cases reported and fewer influenza A outbreaks from September 1 to November 19 in the current 2011-2012 season.

? The majority of ILI activity in Ontario since the beginning of September to November 19, 2011 can be attributed to entero/rhinovirus.

o The majority of outbreaks (~63.2%) had entero/rhinovirus identified as the causative organism (Table 3).

o Entero/rhinovirus has had the highest percent positivity among laboratory tests of respiratory samples for the current week and season to date (Table 2). However, entero/virus activity in week 46 (6.44% positivity) declined somewhat as compared to week 45 (8.25% positivity).

[...]

Full report:

http://www.oahpp.ca/resources/documents/flubulletin/Influenza%20Bulletin-Week%2046.pdf

**Pathfinder** · December 2, 2011, 05:43 PM

Re: Ontario Influenza Bulletin 2011-2012 - Surveillance Week 47

Ontario Influenza Bulletin I 2011-2012
SURVEILLANCE WEEK 47 (November 20, 2011 ? November 26, 2011)

Ontario Influenza Bulletin, 2011-2012 (September 1, 2011 ? November 26, 2011)
Produced by: Surveillance and Epidemiology Program,
Public Health Ontario

Summary of current and season to date influenza activity

? There has been little to no influenza activity for the 2011-2012 season to date although activity appears to be increasing:

o Influenza activity appears to be increasing in Ontario. Five cases of influenza were identified from Middlesex-London (2), Toronto (1), Simcoe-Muskoka (1) and Hamilton (1) health units in week 47. Prior to week 47 only four cases had been identified since September 1. A total of 9 influenza cases have been identified for the 2011-2012 surveillance season to date. Cases have been identified in several health units around the province (Table 1). Currently, the majority of cases reported to date have been identified with the H3 subtype (6/9).

o Of the cases of influenza that have been reported, 66.7% (6/9) have been hospitalized.

o Compared to the same period in the 2010-2011 season, fewer cases and fewer influenza A outbreaks were reported this season from September 1 to November 26.

? The majority of ILI activity in Ontario from September 1 to November 26, 2011 can be attributed to entero/rhinovirus.

o The majority of outbreaks (~60.8%) had entero/rhinovirus identified as the causative organism (Table 3).

o Entero/rhinovirus has had the highest percent positivity among laboratory tests of respiratory samples for the current week and for the season to date (Table 2). Entero/virus activity in week 47 (9.98% positivity) increased in comparison to week 46
(6.44% positivity).

Full report:

http://www.oahpp.ca/resources/documents/flubulletin/Influenza%20Bulletin-Week%2047.pdf

**Pathfinder** · December 9, 2011, 04:24 PM

Re: Ontario Influenza Bulletin 2011-2012 - Surveillance Week 48

Ontario Influenza Bulletin I 2011-2012
SURVEILLANCE WEEK 48 (November 27, 2011 ? December 3, 2011)
...

Ontario Influenza Bulletin, 2011-2012 (September 1, 2011 ? December 3, 2011)
Page 2 of 13
Produced by: Surveillance and Epidemiology Program,
Public Health Ontario

Summary of current and season to date influenza activity

? There has been very little influenza activity for the 2011-2012 season to date although activity has increased recently:

o Influenza activity continues to be seen at low levels. Three cases of influenza were identified from North Bay Parry Sound District (1), Peel (1) and Toronto (1) health units in week 48. Prior to week 48 only nine cases had been identified since September 1. A total of 12 influenza cases have been identified for the 2011-2012 surveillance season to date. Cases have now been identified in all regions of the province (Table 1). Currently, half

of the cases reported to date have been identified with the influenza A/H3 subtype (6/12).

o Of the cases of influenza that have been reported, 66.7% (8/12) have been hospitalized.

o Compared to the same period in the 2010-2011 season, fewer cases and fewer influenza outbreaks were reported this season from September 1 to December 3.

? The majority of ILI activity in Ontario from September 1 to December 3, 2011 can be attributed to entero/rhinovirus, however parainfluenza virus activity has increased in the past two weeks:

o The majority of outbreaks (~57.4%) had entero/rhinovirus identified as the causative organism (Table 3), but more parainfluenza related outbreaks have been observed in recent weeks (Figure 4).

o Entero/rhinovirus has had the highest percent positivity among laboratory tests of respiratory samples for the season to date (Table 2), but entero/rhinovirus activity in week 48 (3.57% positivity) decreased in comparison to week 47 (9.98% positivity).

o In week 48 the highest percent positivity among laboratory tests of respiratory samples was for parainfluenza virus at 8.26% compared to 8.73% in week 47 and 4.30% in week 46.

Full report:

http://www.oahpp.ca/resources/documents/flubulletin/Influenza%20Bulletin-Week%2048.pdf

**Pathfinder** · December 16, 2011, 01:02 PM

Re: Ontario Influenza Bulletin 2011-2012 - Surveillance Week 49

Ontario Influenza Bulletin I 2011-2012
SURVEILLANCE WEEK 49 (December 4, 2011 ? December 10, 2011)

Ontario Influenza Bulletin, 2011-2012 (September 1, 2011 ? December 10, 2011)
Page 2 of 13
Produced by: Surveillance and Epidemiology Program,
Public Health Ontario

Summary of current and season to date influenza activity

 There has been very little influenza activity for the 2011-2012 season to date and activity has been stable recently:

o Influenza activity continues to be seen at low levels. A total of 15 influenza cases have been identified for the 2011-2012 surveillance season to date. Three cases of influenza were identified from Wellington-Dufferin-Guelph (1) and Peel (2) health units in week 49. Prior to week 49, only 12 cases were reported since September 1. Cases have been identified in all regions of the province (Table 1). Almost half of the cases reported to date were subtyped as influenza A/H3 (7/15).

o Compared to the same period in the 2010-2011 season, fewer cases and fewer influenza outbreaks were reported this season from September 1 to December 10.

 While the majority of ILI activity in Ontario from September 1 to December 10, 2011 can be attributed to entero/rhinovirus, currently entero/rhinovirus activity is quite low:

o The majority of outbreaks (57.2%) this season had entero/rhinovirus identified as the causative organism (Table 3).

o Entero/rhinovirus has had the highest percent positivity among laboratory tests of respiratory samples for the season to date (Table 2), but entero/rhinovirus activity in week 49 remained low (4.32% positivity), increasing slightly in comparison to week 48 (3.57% positivity).

o In week 49 the highest percent positivity among laboratory tests of respiratory samples was for RSV at 10.14% compared to 5.52% in week 48.

Full report:

http://www.oahpp.ca/resources/documents/flubulletin/Influenza%20Bulletin-Week%2049.pdf

**Pathfinder** · December 31, 2011, 10:31 AM

Re: Ontario Influenza Bulletin 2011-2012 - Surveillance Week 50

Ontario Influenza Bulletin I 2011-2012
SURVEILLANCE WEEK 50 (December 11, 2011 ? December 17, 2011)

Ontario Influenza Bulletin, 2011-2012 (September 1, 2011 ? December 17, 2011)
Produced by: Surveillance and Epidemiology Program,
Public Health Ontario

Summary of current and season to date influenza activity

 There has been very little influenza activity for the 2011-2012 season to date and activity has been stable recently:

o Influenza activity continues to be seen at low levels. A total of 21 influenza cases have been reported for the 2011-2012 surveillance season to date. Six cases of influenza were identified from Middlesex-London (1), Toronto (3), Waterloo (1) and York Region (1) health units in week 50. Prior to week 50, only 15 cases were reported since September 1. Cases have been identified in all regions of the province (Table 1). Over one third of the cases reported to date were subtyped as influenza A/H3 (8/21).

o Compared to the same period in the 2010-2011 season, fewer cases and fewer influenza outbreaks were reported this season from September 1 to December 17.

 While the majority of ILI activity in Ontario from September 1 to December 17, 2011 can be attributed to entero/rhinovirus, currently entero/rhinovirus activity is quite low:

o The majority of outbreaks (54.4%) this season had entero/rhinovirus identified as the causative organism (Table 3).

o Entero/rhinovirus has had the highest percent positivity among laboratory tests of respiratory samples for the season to date (Table 2), but entero/rhinovirus activity in week 50 remained low (3.17% positivity), decreasing slightly in comparison to week 49 (4.32% positivity).

o In week 50 the highest percent positivity among laboratory tests of respiratory samples was for RSV at 13.52% compared to 10.14% in week 49 and 5.52% in week 48.

Full report:

http://www.oahpp.ca/resources/documents/flubulletin/Influenza%20Bulletin-Week%2050.pdf

**Pathfinder** · January 6, 2012, 06:05 PM

Re: Ontario Influenza Bulletin 2011-2012 - Surveillance Weeks 51-52

Ontario Influenza Bulletin I 2011-2012
SURVEILLANCE WEEKS 51 & 52 (December 18, 2011 – December 31, 2011)

Ontario Influenza Bulletin, 2011-2012 (September 1, 2011 – December 31, 2011)
Produced by: Surveillance and Epidemiology Program,
Public Health Ontario

Summary of current and season to date influenza activity

 Influenza activity for the 2011-2012 season has been lower than in previous years to date; however, activity has been increasing recently:

o Influenza activity continued to increase slowly over the last three weeks. A total of 47 influenza cases have been reported for the 2011-2012 surveillance season to date. Fifteen cases of influenza were identified in week 52, they were from Halton Region (1), Hamilton (1), Niagara Region (1), Ottawa (1), Peel Region (2), Toronto (8) and Wellington-Dufferin-Guelph (1) health units. Eleven cases were reported in week 51. Cases have been identified in all regions of the province (Table 1).

o Approximately two-thirds of cases reported to date were subtyped as influenza A(H1N1)pdm09 and influenza B, with each subtype accounting for 14 cases. In recent weeks most influenza A cases have been identified as (H1N1)pdm09, whereas earlier in the season most were identified as H3N2.

o Compared to the same period in the 2010-2011 season, fewer cases and fewer influenza outbreaks were reported this season from September 1 to December 31.

 The cause(s) of ILI in Ontario from September 1 to December 31, 2011 has changed as the season progressed:

o The majority of outbreaks (50.6&#37

this season had entero/rhinovirus identified as the causative organism (Table 3). However, all of the rhinovirus outbreaks occurred prior to week 50.

o Entero/rhinovirus has had the highest percent positivity among laboratory tests of respiratory samples for the season to date (Table 2), but entero/rhinovirus activity has declined since week 49. In week 52, it remained low (2.95% positivity), decreasing slightly in comparison to week 50 (3.17% positivity).

o In week 52 the highest percent positivity among laboratory tests of respiratory samples was for RSV at 19.7% compared to 13.52% in week 50 and 10.14% in week 49.

Full report:
http://www.oahpp.ca/resources/docume...eks%205152.pdf

**Pathfinder** · January 13, 2012, 09:15 PM

Re: Ontario Influenza Bulletin 2011-2012 - Surveillance Week 1

Ontario Influenza Bulletin I 2011-2012
SURVEILLANCE WEEK 1 (January 1, 2012 ? January 7, 2012)

Ontario Influenza Bulletin, 2011-2012 (September 1, 2011 ? January 7, 2012)
Produced by: Surveillance and Epidemiology Program,
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; however, activity has been increasing recently:

o A total of 78 influenza cases have been reported for the 2011-2012 surveillance season to date, 30 of which were reported during week 1. Cases identified in week 1 were from Durham (1), Halton Region (1), Hamilton (2), Middlesex-London (1), North Bay Parry Sound District (1), Oxford County (1), Peel Region (11), Toronto (9), Waterloo Region (2) and York Region (1) health units. In comparison, 15 cases were reported in week 52. Cases have been identified in all regions of the province (Table 1).

o Approximately two-thirds of cases reported to date were subtyped as influenza A(H1N1)pdm09 (22 cases) and influenza B (27 cases), which together account for 62.8% (49/78) of cases this season. In recent weeks, most influenza A cases have been identified as (H1N1)pdm09, whereas earlier in the season, most were identified as H3N2.

o Approximately two-thirds of cases have been children under 5 years old (31 cases) and adults over the age of 65 (15 cases), which together account for 59.0% (46/78) of cases reported to date. The highest number of cases (23) occurred in the 1 to 4 year old age group, which represents 29.5% of cases. Among influenza cases that have been hospitalized, 38.7% (12/31) were children under 5 years old and 32.2% (10/31) have been in adults over the age of 65.

o Compared to the same period in the 2010-2011 season, fewer cases and fewer influenza outbreaks were reported this season from September 1 to January 7.

 The cause(s) of ILI in Ontario from September 1 to January 7, 2011 has changed as the season progressed:

o Entero/rhinovirus has been identified as the causative organism in 46.5% (92/198) of institutional respiratory infection outbreaks this season (Table 3). However, almost all of the rhinovirus outbreaks occurred prior to week 50.

o Entero/rhinovirus and RSV have had the highest percent positivity among laboratory tests of respiratory samples for the season to date (Table 2), with RSV activity increasing steadily since week 44. RSV has had the highest percent positivity among cases since week 49.

o Increases in ILI consultation rate from 30.53 per 1,000 patient visits in week 52 to 41.27 per 1,000 patient visits in week 1 were driven by higher rates in the 0-4 age group (170.94 per 1,000 visits).

Full report:

http://www.oahpp.ca/resources/documents/flubulletin/Influenza%20Bulletin-Week%2001.pdf

**Pathfinder** · January 20, 2012, 05:21 PM

Re: Ontario Influenza Bulletin 2011-2012 - Surveillance Week 2

Ontario Influenza Bulletin I 2011-2012
SURVEILLANCE WEEK 2 (January 8, 2012 ? January 14, 2012)

Ontario Influenza Bulletin, 2011-2012 (September 1, 2011 ? January 14, 2012)
Produced by: Surveillance and Epidemiology Program,
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; however, activity continues to increase:

o A total of 111 influenza cases have been reported for the 2011-2012 surveillance season to date, 33 of which were reported during week 2. Cases identified in week 2 were from Eastern Ontario (1); Haliburton, Kawartha, Pine Ridge (1); Halton Region (2); Hamilton (2); Hastings and Prince Edward Counties (1); Middlesex-London (3); Peel Region (8); Simcoe Muskoka District (1); Toronto (12); and Wellington-Dufferin-Guelph (2) health units. Cases have been identified in all regions of the province (Table 1).

o The majority of influenza cases reported to date were subtyped as influenza A(H1N1)pdm09 (29 cases) or influenza B (42 cases), which together account for 64.0% (71/111) of cases this season.

o The majority of influenza cases this season have been children under 5 years old (43 cases) and adults 65 years of age and older (22 cases), which together account for 58.6% (65/111) of cases reported to date. The highest number of cases (31) occurred in the 1 to 4 year old age group, which represents 27.9% of cases.

o Among influenza cases that have been hospitalized, 31.8% (14/44) were children under 5 years old and 29.5% (13/44) were in adults over the age of 65.

o Compared to the same period in the 2010-2011 season, fewer cases and fewer influenza outbreaks were reported this season from September 1 to January 14.

 The cause(s) of ILI in Ontario from September 1 to January 14, 2012 has changed as the season progressed:

o Entero/rhinovirus has been identified as the causative organism in 43.1% (93/216) of institutional respiratory infection outbreaks this season (Table 3). However, almost all of the rhinovirus outbreaks occurred prior to week 50. In recent weeks RSV has been the primary causative organism identified in institutional outbreaks.

o RSV has had the highest percent positivity among laboratory tests of respiratory samples for the season to date (Table 2), with activity increasing steadily since week 44. RSV has had the highest percent positivity among cases each week since week 49.

o Coronavirus activity has started to increase recently.

Full report:

http://www.oahpp.ca/resources/documents/flubulletin/Influenza%20Bulletin-Week%202.pdf

**Pathfinder** · January 27, 2012, 06:12 PM

Re: Ontario Influenza Bulletin 2011-2012 - Surveillance Week 3

Ontario Influenza Bulletin I 2011-2012
SURVEILLANCE WEEK 3 (January 15, 2012 ? January 21, 2012)

Ontario Influenza Bulletin, 2011-2012 (September 1, 2011 ? January 21, 2012)
Produced by: Surveillance and Epidemiology Program,
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 150 influenza cases have been reported for the 2011-2012 surveillance season to date, 38 of which were reported during week 3. Cases identified in week 3 were from Brant County (2); Grey Bruce (1); Haliburton, Kawartha, Pine Ridge (2); Halton Region (2); Hamilton (2); Kingston, Frontenac, Lennox & Addington (1); North Bay Parry Sound District (1); Ottawa (4); Peel region (8); Simcoe Muskoka District (2); Toronto (8); Waterloo Region (1); and Wellington-Dufferin-Guelph (4)) health units. Cases have been identified in all regions of the province (Table 1).

o The majority of influenza cases reported for the 2011-2012 season to date were subtyped as influenza A(H1N1)pdm09 (35 cases) or influenza B (61 cases), which together account for 64.0% (96/150) of cases this season.

o The majority of influenza cases this season have been children under 5 years old (55 cases) and adults 65 years of age and older (32 cases), which together account for 58.0% (87/150) of cases reported to date. The highest number of cases (39) has occurred in the 1 to 4 year old age group, which represents 26.0% of cases.

o Among influenza cases that have been hospitalized, 33.9% (19/56) were children under 5 years old and 30.4% (17/56) were in adults over the age of 65.

o Compared to the same period in the 2010-2011 season, fewer cases and fewer influenza outbreaks were reported this season from September 1 to January 21.

 The cause(s) of ILI in Ontario from September 1, 2011 to January 21, 2012 has changed as the season progressed:

o Entero/rhinovirus has been identified as the causative organism in 39.5% (94/238) of institutional respiratory infection outbreaks this season (Table 3). However, almost all of the rhinovirus outbreaks occurred prior to week 50. In the last three weeks, three institutional influenza outbreaks (two influenza B outbreaks and one influenza A outbreak) have been reported.

o RSV has had the highest percent positivity among laboratory tests of respiratory samples for the season to date (Table 2), with activity increasing steadily since week 44. RSV has had the highest percent positivity among isolates submitted for testing each week since week 49.

o Coronavirus activity increased steadily between week 51 and week 2, and remains relatively high this week with a percent positivity of 9.89%.

Full report:

http://www.oahpp.ca/resources/documents/flubulletin/Influenza%20Bulletin-Week%203.pdf

**Pathfinder** · February 3, 2012, 04:46 PM

Re: Ontario Influenza Bulletin 2011-2012 - Surveillance Week 4

Ontario Influenza Bulletin I 2011-2012
SURVEILLANCE WEEK 4 (January 22, 2012 ? January 28, 2012)

Ontario Influenza Bulletin, 2011-2012 (September 1, 2011 ? January 28, 2012)
Produced by: Surveillance and Epidemiology Program,
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 191 influenza cases have been reported for the 2011-2012 surveillance season to date, 38 of which were reported during week 4. Cases identified in week 4 were from Durham Region (2); Haliburton, Kawartha, Pine Ridge (1); Halton Region (3); Hamilton (4); Niagara Region (1); Peel Region (8); Simcoe Muskoka District (2); Toronto (16); and York Region (1) health units. Cases have been identified in all regions of the province (Table 1).

o The majority of influenza cases reported for the 2011-2012 season to date were subtyped as influenza A(H1N1)pdm09 (55 cases) or influenza B (72 cases), which together account for 66.5% (127/191) of cases this season.

o The majority of influenza cases this season have been children under 5 years old (67 cases) and adults 65 years of age and older (38 cases), which together account for 55.0% (105/191) of cases reported to date. The highest number of cases (49) has occurred in the 1 to 4 year old age group, which represents 25.7% of cases.

o Among influenza cases that have been hospitalized, 33.8% (22/65) were children under 5 years old and 26.2% (17/65) were in adults over the age of 65.

o Compared to the same period in the 2010-2011 season, fewer cases and fewer influenza outbreaks have been reported this season from September 1 to January 28.

 The cause(s) of ILI in Ontario from September 1, 2011 to January 21, 2012 has changed as the season progressed:

o Since week 1, seven institutional influenza outbreaks (two influenza A outbreaks and five influenza B outbreaks) have been reported. Entero/rhinovirus has been identified as the causative organism in 37.9% (97/256) of institutional respiratory infection outbreaks this season (Table 3). However, almost all of the rhinovirus outbreaks occurred prior to week 50.

o Coronavirus had the highest percent positivity among laboratory tests of respiratory samples during week 4 at 17.33% (Table 2). Coronavirus activity has been increasing since week 51.

o RSV has had the highest percent positivity among isolates submitted for testing for the season to date at 10.68%. RSV had the highest percent positivity among isolates submitted for testing each week between week 49 and week 3, but showed decreased activity this week.

Full report:

http://www.oahpp.ca/resources/documents/flubulletin/Influenza%20Bulletin-Week%204.pdf

**Pathfinder** · February 10, 2012, 05:54 PM

Re: Ontario Influenza Bulletin 2011-2012 - Surveillance Week 5

Ontario Influenza Bulletin I 2011-2012
SURVEILLANCE WEEK 5 (January 29, 2012 ? February 4, 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 253 influenza cases have been reported for the 2011-2012 surveillance season to date, 60 of which were reported during week 5.

o The majority of influenza cases reported for the 2011-2012 season to date were subtyped as influenza A(H1N1)pdm09 (62 cases) or influenza B (111 cases), which together account for 68.4% (173/253) of cases this season.

o The majority of influenza cases this season have been children under 5 years old (89 cases) and adults 65 years of age and older (50 cases), which together account for 54.9% (139/253) of cases reported to date.
The highest number of cases (62) has occurred in the 1 to 4 year old age group, which represents 24.5% of cases.

o Among influenza cases that have been hospitalized, 33.7% (28/83) were children under 5 years old and 24.1% (20/83) 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 4, 2012.

 The cause(s) of ILI in Ontario from September 1, 2011 to February 4, 2012 has changed as the season progressed:

o Since week 1, nine institutional influenza outbreaks have been reported: three influenza A, five influenza B, and one combined A and B outbreak. Since week 1, RSV 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 5 at 23.30% (Table 3). RSV has had the highest percent positivity among isolates submitted for testing for the season to date at 11.65%.

o Levels of coronavirus have been increasing since week 51. For week 5, coronavirus had a percent positivity of 15.11%.

Full report:

http://www.oahpp.ca/resources/documents/flubulletin/Influenza%20Bulletin-Week%205.pdf

**Pathfinder** · February 17, 2012, 04:44 PM

Re: Ontario Influenza Bulletin 2011-2012 - Surveillance Week 6

Ontario Influenza Bulletin I 2011-2012
SURVEILLANCE WEEK 6 (February 5, 2012 ? February 11, 2012)

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, but activity has been increasing recently:

o A total of 355 influenza cases have been reported for the 2011-2012 surveillance season to date, of which 99 were reported during week 6.

o The majority of influenza cases reported for the 2011-2012 season to date were subtyped as influenza A(H1N1)pdm09 (77 cases) or influenza B (181 cases), which together account for 72.7% (258/355) of cases this season.

o The majority of influenza cases this season have been children under 5 years old (124 cases) and adults 65 years of age and older (72 cases), which together account for 55.2% (196/355) of cases reported to date. The highest number of cases (88) has occurred in the 1 to 4 year old age group, which represents 24.8% of cases.

o Among influenza cases that have been hospitalized, 35.8% (39/109) were children under 5 years old and 23.9% (26/109) 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 11, 2012.

 The cause(s) of ILI in Ontario from September 1, 2011 to February 4, 2012 has changed as the season progressed:

o Since week 5, influenza B has been the dominant circulating influenza virus.

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, RSV 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 6 at 22.72% (Table 3). RSV also has had the highest percent positivity among isolates submitted for testing for the season to date at 12.36%.

o Levels of coronavirus have been increasing since week 51. For week 6, coronavirus had a percent positivity of 16.51%.

o The provincial ILI consultation rate increased from 34.14/1,000 patient visits in week 5 to 43.54/1,000 patient visits in week 6, the bulk of which was due to increased rates in the 0-4 age group.

...
Ontario Influenza Bulletin, 2011-2012 (September 1, 2011 ? February 11, 2012)
Page 6 of 14
Produced by: Surveillance and Epidemiology, Public Health Ontario
<TABLE dir=ltr border=1 cellSpacing=0 cellPadding=7 width=550><TBODY><TR><TD height=16 vAlign=top width="20%">Table 2. Number of hospitalizations and deaths among influenza cases during week 6 and cumulative (in brackets) for the season by age group since September 1, 2011 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%"><1

</TD><TD height=7 vAlign=top width="20%">3 (12)

</TD><TD height=7 vAlign=top width="20%">8.48

</TD><TD height=7 vAlign=top width="20%">0 (0)

</TD><TD height=7 vAlign=top width="20%">0.00

</TD></TR><TR><TD height=7 vAlign=top width="20%">1-4

</TD><TD height=7 vAlign=top width="20%">8 (27)

</TD><TD height=7 vAlign=top width="20%">4.74

</TD><TD height=7 vAlign=top width="20%">0 (1)

</TD><TD height=7 vAlign=top width="20%">0.18

</TD></TR><TR><TD height=7 vAlign=top width="20%">5-14

</TD><TD height=7 vAlign=top width="20%">5 (10)

</TD><TD height=7 vAlign=top width="20%">0.67

</TD><TD height=7 vAlign=top width="20%">0 (0)

</TD><TD height=7 vAlign=top width="20%">0.00

</TD></TR><TR><TD height=7 vAlign=top width="20%">15-24

</TD><TD height=7 vAlign=top width="20%">1 (2)

</TD><TD height=7 vAlign=top width="20%">0.11

</TD><TD height=7 vAlign=top width="20%">0 (0)

</TD><TD height=7 vAlign=top width="20%">0.00

</TD></TR><TR><TD height=7 vAlign=top width="20%">25-44

</TD><TD height=7 vAlign=top width="20%">1 (14)

</TD><TD height=7 vAlign=top width="20%">0.38

</TD><TD height=7 vAlign=top width="20%">0 (0)

</TD><TD height=7 vAlign=top width="20%">0.00

</TD></TR><TR><TD height=7 vAlign=top width="20%">45-64

</TD><TD height=7 vAlign=top width="20%">2 (18)

</TD><TD height=7 vAlign=top width="20%">0.49

</TD><TD height=7 vAlign=top width="20%">0 (0)

</TD><TD height=7 vAlign=top width="20%">0.00

</TD></TR><TR><TD height=7 vAlign=top width="20%">65+

</TD><TD height=7 vAlign=top width="20%">6 (26)

</TD><TD height=7 vAlign=top width="20%">1.42

</TD><TD height=7 vAlign=top width="20%">1 (4)

</TD><TD height=7 vAlign=top width="20%">0.22

</TD></TR><TR><TD height=7 vAlign=top width="20%">Total

</TD><TD height=7 vAlign=top width="20%">26 (109)

</TD><TD height=7 vAlign=top width="20%">0.83

</TD><TD height=7 vAlign=top width="20%">1 (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%20Bulletin-Week%206.pdf

**Pathfinder** · February 24, 2012, 01:04 PM

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. 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 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%"><1

</TD><TD height=7 vAlign=top width="20%">6 (18)

</TD><TD height=7 vAlign=top width="20%">12.71

</TD><TD height=7 vAlign=top width="20%">0 (0)

</TD><TD height=7 vAlign=top width="20%">0.00

</TD></TR><TR><TD height=7 vAlign=top width="20%">1-4

</TD><TD height=7 vAlign=top width="20%">7 (34)

</TD><TD height=7 vAlign=top width="20%">5.96

</TD><TD height=7 vAlign=top width="20%">0 (1)

</TD><TD height=7 vAlign=top width="20%">0.18

</TD></TR><TR><TD height=7 vAlign=top width="20%">5-14

</TD><TD height=7 vAlign=top width="20%">6 (16)

</TD><TD height=7 vAlign=top width="20%">1.07

</TD><TD height=7 vAlign=top width="20%">0 (0)

</TD><TD height=7 vAlign=top width="20%">0.00

</TD></TR><TR><TD height=7 vAlign=top width="20%">15-24

</TD><TD height=7 vAlign=top width="20%">1 (3)

</TD><TD height=7 vAlign=top width="20%">0.17

</TD><TD height=7 vAlign=top width="20%">0 (0)

</TD><TD height=7 vAlign=top width="20%">0.00

</TD></TR><TR><TD height=7 vAlign=top width="20%">25-44

</TD><TD height=7 vAlign=top width="20%">2 (16)

</TD><TD height=7 vAlign=top width="20%">0.44

</TD><TD height=7 vAlign=top width="20%">0 (0)

</TD><TD height=7 vAlign=top width="20%">0.00

</TD></TR><TR><TD height=7 vAlign=top width="20%">45-64

</TD><TD height=7 vAlign=top width="20%">2 (20)

</TD><TD height=7 vAlign=top width="20%">0.54

</TD><TD height=7 vAlign=top width="20%">0 (0)

</TD><TD height=7 vAlign=top width="20%">0.00

</TD></TR><TR><TD height=7 vAlign=top width="20%">65+

</TD><TD height=7 vAlign=top width="20%">10 (36)

</TD><TD height=7 vAlign=top width="20%">1.96

</TD><TD height=7 vAlign=top width="20%">0 (4)

</TD><TD height=7 vAlign=top width="20%">0.22

</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%20Bulletin-Week%207.pdf

**Pathfinder** · March 2, 2012, 06:58 PM

Re: Ontario Influenza Bulletin 2011-2012 - Surveillance Week 8

Ontario Influenza Bulletin I 2011-2012
SURVEILLANCE WEEK 8 (February 19, 2012 ? February 25, 2012)

Ontario Influenza Bulletin, 2011-2012 (September 1, 2011 ? February 25, 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 678 influenza cases have been reported for the 2011-2012 surveillance season to date, of which 170 were reported during week 8.

o The majority of influenza cases reported for the 2011-2012 season to date were subtyped as influenza A(H1N1)pdm09 (115 cases) or influenza B (394 cases), which together account for 75.1% (509/678) of cases this season.

o The majority of influenza cases this season have been children under 5 years old (204 cases) and adults 65 years of age and older (133 cases), which together account for 49.7% (337/678) of cases reported to date. The highest number of cases (140) has occurred in the 1 to 4 year old age group, which represents 20.7% of cases.

o Among influenza cases that have been hospitalized, 36.2% (67/185) were children under 5 years old and 24.9% (46/185) 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 25, 2012.

? The cause(s) of ILI in Ontario from September 1, 2011 to February 25, 2012 has changed as the season progressed:

o Since week 5, influenza B has been the dominant circulating influenza virus. Of the 180 influenza B isolates that have been characterized at the National Microbiology Laboratory, 101 (56.1%) are a different strain (B/Wisconsin/01/2010-like) and lineage and is not contained in this season?s trivalent influenza vaccine. The World Health Organization has recommended the inclusion of this strain in the vaccine for the 2012-2013 influenza season for the Northern Hemisphere.

o Since week 1, 20 institutional influenza outbreaks have been reported: six influenza A, 13 influenza B, and one combined A and B outbreak.

o RSV had the highest percent positivity among laboratory tests of respiratory samples during week 8 at 22.79% (Table 3). RSV also has had the highest percent positivity among isolates submitted for testing for the season to date at 13.50%.

o Coronavirus has had a percent positivity above 5% each week since week 52. For week 8, coronavirus had a percent positivity of 14.46%.
...
Ontario Influenza Bulletin, 2011-2012 (September 1, 2011 ? February 25, 2012)

Produced by: Surveillance and Epidemiology, Public Health Ontario

<TABLE dir=ltr border=1 cellSpacing=0 cellPadding=7 width=567><TBODY><TR><TD height=18 vAlign=top width="20%">Table 2. Number of hospitalizations and deaths among influenza cases during week 8 and cumulative (in brackets) for the season by age group since September 1, 2011 Age Group

</TD><TD height=18 vAlign=top width="20%">Number of Hospitalizations

</TD><TD height=18 vAlign=top width="20%">Cumulative Rate per 100,000

</TD><TD height=18 vAlign=top width="20%">Number of Deaths

</TD><TD height=18 vAlign=top width="20%">Cumulative Rate per 100,000

</TD></TR><TR><TD height=9 vAlign=top width="20%"><1

</TD><TD height=9 vAlign=top width="20%">3 (21)

</TD><TD height=9 vAlign=top width="20%">14.83

</TD><TD height=9 vAlign=top width="20%">0 (0)

</TD><TD height=9 vAlign=top width="20%">0.00

</TD></TR><TR><TD height=9 vAlign=top width="20%">1-4

</TD><TD height=9 vAlign=top width="20%">12 (46)

</TD><TD height=9 vAlign=top width="20%">8.07

</TD><TD height=9 vAlign=top width="20%">0 (1)

</TD><TD height=9 vAlign=top width="20%">0.18

</TD></TR><TR><TD height=9 vAlign=top width="20%">5-14

</TD><TD height=9 vAlign=top width="20%">10 (26)

</TD><TD height=9 vAlign=top width="20%">1.74

</TD><TD height=9 vAlign=top width="20%">0 (0)

</TD><TD height=9 vAlign=top width="20%">0.00

</TD></TR><TR><TD height=9 vAlign=top width="20%">15-24

</TD><TD height=9 vAlign=top width="20%">0 (3)

</TD><TD height=9 vAlign=top width="20%">0.17

</TD><TD height=9 vAlign=top width="20%">0 (0)

</TD><TD height=9 vAlign=top width="20%">0.00

</TD></TR><TR><TD height=9 vAlign=top width="20%">25-44

</TD><TD height=9 vAlign=top width="20%">3 (19)

</TD><TD height=9 vAlign=top width="20%">0.52

</TD><TD height=9 vAlign=top width="20%">0 (0)

</TD><TD height=9 vAlign=top width="20%">0.00

</TD></TR><TR><TD height=9 vAlign=top width="20%">45-64

</TD><TD height=9 vAlign=top width="20%">4 (24)

</TD><TD height=9 vAlign=top width="20%">0.65

</TD><TD height=9 vAlign=top width="20%">0 (0)

</TD><TD height=9 vAlign=top width="20%">0.00

</TD></TR><TR><TD height=9 vAlign=top width="20%">65+

</TD><TD height=9 vAlign=top width="20%">10 (46)

</TD><TD height=9 vAlign=top width="20%">2.51

</TD><TD height=9 vAlign=top width="20%">2 (6)

</TD><TD height=9 vAlign=top width="20%">0.33

</TD></TR><TR><TD height=9 vAlign=top width="20%">Total

</TD><TD height=9 vAlign=top width="20%">42 (185)

</TD><TD height=9 vAlign=top width="20%">1.40

</TD><TD height=9 vAlign=top width="20%">2 (7)

</TD><TD height=9 vAlign=top width="20%">0.05

</TD></TR></TBODY></TABLE>

...

Full report:
http://www.oahpp.ca/resources/documents/flubulletin/Influenza%20Bulletin-Week%208.pdf

Announcement

Ontario Influenza Bulletin 2011-2012 - Surveillance Season (September 1, 2011 ? September 1, 2012) - 1223 hospitalizations and 79 deaths total

Ontario Influenza Bulletin 2011-2012 - Surveillance Season (September 1, 2011 ? September 1, 2012) - 1223 hospitalizations and 79 deaths total

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