527. The Effect of Rates of Staff Influenza Vaccination and Reporting Time of Influenza Outbreaks on the Duration of Nursing Home Influenza Outbreaks in Maryland
Session: Poster Session: Hospital-acquired and Transplant Infections
Friday, October 30, 2009: 12:00 AM
Room: Poster Hall A
Background: One of the major concerns in nursing homes (NH) during an influenza outbreak is the length of the outbreak, due to the financial burden it places on the facility and the discomfort the prolonged control measures placed on residents. Staff influenza vaccination rates and the length of time for NH reporting an outbreak to the local health department (LHD) and subsequent placement of infection control measures at the facility were examined individually to determine effect on the duration of influenza outbreaks in NH.
Methods: The investigation included review of the DHMH outbreak database as well review of randomly selected outbreak files of influenza outbreaks in Maryland NH. Twenty-three outbreaks were randomly selected from the 146 confirmed influenza NH outbreaks from 2004-2008 for the staff immunization review. Correlation coefficients and t-tests were used to compare and examine the relationship between the variables.
Results: Both staff influenza vaccination rates and the outbreak report time to the LHD were shown to effect duration of outbreaks in NH. Though a low correlation coefficient (0.25), the trend line of the scatter plot inferred that as vaccination rates increased, the duration of outbreaks decreased. A stronger correlation coefficient (0.5) was found when comparing report time to the LHD and the duration of outbreak. Further investigation into specific control measures found a strong positive correlation (0.83) between the report time and the number of days closed to admissions. The trend line showed that for every day that the outbreak was not reported, the NH was closed to admissions approximately an additional 0.89 days. A t-test was showed that there were no significant differences between smaller and larger NH (resident population) and the respective duration of outbreaks (p=0.96).
Conclusion: Increasing staff influenza rates and reporting/implementing control measures in an influenza outbreak as soon as possible may shorten the duration of the outbreak in nursing homes and in turn lessen the financial and residential burden placed upon the facility and its residents.
David Blythe, MD, MPH, Alvina Chu, MHS2, Shawn Kiernan, MPH2, Brenda Roup, PhD, RN2, Lucy Wilson, MD2 and  S. Kiernan, None..
L. E. Wilson, None..
B. Roup, None..
D. Blythe, None..
A. Chu, None., (1)Maryland Department of Health and Mental Hygiene, Baltimore, MD