Skip directly to search Skip directly to A to Z list Skip directly to site content
CDC Home

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 5

Risk factors for symptomatic influenza infection in health care workers in acute care hospitals during 2009 pandemic, Toronto, Ontario, Canada*

Risk factor OR (95% CI),
adjusted† OR (95% CI),
multivariable‡
Age, y, per 10 y increase 0.99 (0.63–1.56) NA
Sex, F
1.79 (0.23–14.04)
NA
Potential exposure conditions
Receipt of A(H1N1)pdm09 vaccine§ 0.49 (0.07–3.67)¶ 0.40 (0.04–3.99)
Weekly specimens yielding influenza, %, per 5% increase 1.56 (1.29–1.88) # 1.43 (1.17–1.73)
Child <18 y in household 3.33 (1.00–11.05) NA
Contact with family member with ARI in prior week 7.26 (2.15–24.54) 7.86 (2.20–28.04)
Contact with co-worker with ARI in prior week 1.40 (0.16–12.40) NA
Cared for patient with ARI in prior week 1.50 (0.44–5.14) NA
Adherence to hand hygiene recommendations, per 10% increase 0.84 (0.73–0.98) 0.86 (0.74–0.99)
Adherence to facial protection recommendations, per 10% increase 0.92 (0.79–1.07) NA
No. AGMP performed or assisted during previous week, per 10 procedures increase** 2.29 (1.26–4.17) 1.95 (1.10–3.48)

*Generalized estimating equation logistic regression analysis of constant and time-varying risk factors for influenza infection in 563 health care workers in acute care hospitals, Influenza Cohort Study, followed during June 2009–April 2010, OR, odds ratio; A(H1N1)pdm09: pandemic influenza A(H1N1) 2009 virus; NA, not applicable; ARI: acute respiratory illness; AGMP: aerosol-generating medical procedures.
†Adjusted for receipt of A(H1N1)pdm09 vaccine and weekly percentage of specimens yielding influenza.
‡Multivariable model including all variables with ORs listed below.
§Participants who had acquired A(H1N1)pdm09 <7 d after vaccination were considered unprotected.
¶Adjusted for weekly percentage of specimens yielding influenza only.
#Undadjusted.
**AGMP are defined as any one of the following: administration of nebulized therapy or humidified oxygen at >40%, use of bag-valve mask, manual ventilation, noninvasive ventilation, open airway suctioning, bronchoscopy or other upper airway endoscopy, tracheostomy, endotracheal intubation, cardiopulmonary resuscitation, oscillatory ventilation, any procedure performed that involves manipulation of open ventilator tubing in a mechanically ventilated patient, sputum induction or other deliberate induction of coughing; OR for being in the same room during AGMP (>1/week) 6.63 (95% CI 2.05–21.41); OR for participants performing AGMP (>1/week) 4.21 (1.12–15.76).

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.

Top of Page

USA.gov: The U.S. Government's Official Web PortalDepartment of Health and Human Services
Centers for Disease Control and Prevention   1600 Clifton Rd. Atlanta, GA 30333, USA
800-CDC-INFO (800-232-4636) TTY: (888) 232-6348 - Contact CDC–INFO