253122 Relationship between antiviral chemoprophylaxis and resident deaths during influenza outbreaks in long-term care facilities during the 2010/11 influenza season in Pennsylvania

Wednesday, November 2, 2011

Erica E. Smith, MPH , Bureau of Epidemiology, Pennsylania Department of Health/CSTE Applied Epiemiology Fellowship Program, Harrisburg, PA
Owen Simwale, MPH , Bureau of Epidemiology, Pennsylvania Department of Health, Harrisburg, PA
Perrianne Lurie, MD, MPH , Bureau of Epidemiology, Pennsylvania Department of Health, Harrisburg, PA
Stephen Ostroff, MD , Bureau of Epidemiology, Pennsylvania Department of Health, Harrisburg, PA
Background. Influenza causes morbidity and mortality among long-term care facility (LTCF) residents. Antiviral post-exposure chemoprophylaxis is recommended for contacts of influenza cases during institutional outbreaks.

Objective. To evaluate antiviral treatment and chemoprophylaxis for prevention of deaths during LTCF influenza outbreaks.

Methods. In Pennsylvania, one case of laboratory-confirmed influenza in an LTCF resident is reportable as an outbreak. A standard data collection worksheet is used to assess facility characteristics, outbreak size and duration, laboratory confirmation, treatment/prophylaxis, and influenza vaccination during LTCF outbreaks.

Outbreaks reported between September 2010 and April 2011 were evaluated. Outbreaks were excluded if final summary reports or laboratory confirmation were unavailable. Analysis using SAS 9.2 was performed to describe outbreak magnitude and duration. Odds ratios were calculated using simple logistic regression.

Results. During the 2010/11 influenza season, 199 influenza outbreaks were reported, of which 20 (10%) were excluded. The 179 outbreaks occurred in 158 facilities and included 2,235 total resident illnesses (median per outbreak = 7, range 1—136). Deaths were reported in 22 outbreaks (12%). Antiviral treatment or prophylaxis was documented in 92% and 50% of outbreaks, respectively. Oseltamivir was used most commonly for treatment (98%) or prophylaxis (90%). Outbreaks in facilities that provided exposed residents with prophylaxis were less likely to report deaths (OR = 0.283, 95% CI 0.097-0.823).

Conclusions. Systematic data collection on influenza outbreaks allows identification of trends and evaluation of intervention strategies. In Pennsylvania during the 2010/11 influenza season, antiviral chemoprophylaxis used during outbreaks in LTCFs appeared to help prevent resident deaths.

Learning Areas:
Clinical medicine applied in public health
Epidemiology
Protection of the public in relation to communicable diseases including prevention or control
Public health or related research

Learning Objectives:
Discuss the role of antiviral chemoprophylaxis in the control of influenza outbreaks in long-term care facilities.

Keywords: Infectious Diseases, Nursing Homes

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I currently coordinate and oversee the reporting of influenza outbreaks from long-term care facilities in Pennsylvania.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.

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