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Volume 19, Number 4—April 2013

CME ACTIVITY

Risk Factors for Influenza among Health Care Workers during 2009 Pandemic, Toronto, Ontario, Canada

Stefan P. KusterComments to Author , Brenda L. Coleman, Janet Raboud, Shelly McNeil, Gaston De Serres, Jonathan Gubbay, Todd Hatchette, Kevin C. Katz, Mark Loeb, Donald Low, Tony Mazzulli, Andrew Simor, Allison J. McGeer, Stefan P. KusterComments to Author , Brenda L. Coleman, Janet Raboud, Shelly McNeil, Gaston De Serres, Jonathan Gubbay, Todd Hatchette, Kevin C. Katz, Mark Loeb, Donald Low, Tony Mazzulli, Andrew Simor, Allison J. McGeer, and on behalf of the Working Adult Influenza Cohort Study Groupon behalf of the Working Adult Influenza Cohort Study Group
Author affiliations: Mount Sinai Hospital, Toronto, Ontario, Canada (S.P. Kuster, B.L. Coleman, D. Low, T. Mazzulli, A.J. McGeer); University of Toronto, Toronto (B.L. Coleman, J. Raboud, K.C. Katz, D. Low, T. Mazzulli, A. Simor, A.J. McGeer); Dalhousie University, Halifax, Nova Scotia, Canada (S. McNeil, T. Hatchette); Laval University Québec, Québec City, Québec, Canada (G. De Serres); Ontario Agency for Health Protection and Promotion, Toronto (J. Gubbay, D. Low); North York General Hospital, Toronto (K.C. Katz); McMaster University, Hamilton, Ontario, Canada (M. Loeb); Sunnybrook Health Sciences Centre, Toronto (A. Simor).; Mount Sinai Hospital, Toronto, Ontario, Canada (S.P. Kuster, B.L. Coleman, D. Low, T. Mazzulli, A.J. McGeer); University of Toronto, Toronto (B.L. Coleman, J. Raboud, K.C. Katz, D. Low, T. Mazzulli, A. Simor, A.J. McGeer); Dalhousie University, Halifax, Nova Scotia, Canada (S. McNeil, T. Hatchette); Laval University Québec, Québec City, Québec, Canada (G. De Serres); Ontario Agency for Health Protection and Promotion, Toronto (J. Gubbay, D. Low); North York General Hospital, Toronto (K.C. Katz); McMaster University, Hamilton, Ontario, Canada (M. Loeb); Sunnybrook Health Sciences Centre, Toronto (A. Simor).

Main Article

Table 1

Characteristics of study participants in the Influenza Cohort Study performed during 2009 pandemic, Toronto, Ontario, Canada*

Characteristic Participant values by cohort, n = 732
No. HCWs in acute care facilities, n = 563 No. non-HCWs in office settings, n = 169 p value
Mean age, y (± SD) 42.2 (11.3) 45.4 (10.8) 0.001
Female sex
478/563 (84.9)
133/169 (78.7)
0.06
Recipient of vaccine
A(H1N1)pdm09 vaccine† 469/554 (84.7) 66/165 (40.0) <0.001
Seasonal influenza vaccine 2009–10 226/563 (40.1) 41/169 (24.3) <0.001
Seasonal influenza vaccine 2008–09
407/552 (73.7)
76/164 (46.3)
<0.001
Underlying health conditions
Asthma 55/555 (9.9) 14/167 (8.4) 0.56
Diabetes mellitus 22/555 (4.0) 5/165 (3.0) 0.58
Allergies to airborne irritants 235/509 (46.2) 60/155 (38.7) 0.10
Current smoker or smoker in household
73/551 (13.3)
27/163 (16.6)
0.28
Potential exposure conditions
Hand-to-face habits 275/557 (49.4) 76/168 (45.2) 0.35
Wearing of prescription eyeglasses 386/561 (68.8) 119/168 (70.8) 0.62
Reusable water bottle use >1/week 232/556 (41.7) 81/169 (47.9) 0.15
Public transit: >8 trips per week 196/558 (35.1) 45/168 (26.8) 0.04
Group gathering attendance 524/563 (93.1) 150/167 (89.8) 0.17
Face-to-face contacts/d, median (IQR) 10 (5, 20) 10 (5, 20) 0.94
>1 person/bedroom in household 192/551 (34.9) 51/166 (30.7) 0.33
Children in workplace 62/558 (11.1) 9/167 (5.4) 0.03
Child <5 y in household 77/563 (13.7) 10/169 (5.9) 0.006
Child <18 y in household 212/563 (37.7) 59/169 (34.9) 0.52
Child in household attends day care 77/555 (13.9) 16/164 (9.8) 0.17

*Data are no./total (%) unless otherwise specified. HCW, health care worker; A(H1N1)pdm09, pandemic influenza A(H1N1) 2009 virus; IQR, interquartile range.
†Participants who had acquired A(H1N1)pdm09 <7 d after vaccination were considered unprotected.

Main Article

1Additional members of the Working Adult Influenza Cohort Study Group are listed at the end of this article.

1Additional members of the Working Adult Influenza Cohort Study Group are listed at the end of this article.

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