433. Use of Web-Based Influenza Surveillance System for Seasonal and Novel (H1N1) Influenza Activity
Session: Poster Session: Hospital-acquired and Transplant Infections
Friday, October 30, 2009: 12:00 AM
Room: Poster Hall A
Background: A gap in influenza surveillance exists in those with minor influenza-like illness (ILI) symptoms who may not contact the health care system. This gap may also exist during an influenza pandemic, especially when access to an overburdened health care system is limited. The Maryland Resident Influenza Tracking Survey (MRITS), a web-based surveillance tool, was implemented during the 2008-09 influenza season. The incidence of ILI is nationally reported through the health care system via the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet). The MRITS was extended beyond the end of the seasonal influenza surveillance period in order to capture community trends of novel H1N1 flu symptoms during a time when limited statewide laboratory testing was available.
Methods: A web-based survey was created to enroll Maryland residents. Those enrolled provided non-identifying demographic data: month/year of birth, county of residence, influenza vaccine status, and e-mail address. Each week, participants received a link to a secure on-line form for reporting any ILI symptoms (fever, cough, sore throat) or influenza vaccination. The data collected were analyzed and compared with ILINet and other surveillance data. Response characteristics during seasonal influenza and novel influenza periods were compared.
Results: The proportion of participants reporting ILI ranged from 0.5% to 4.2%, peaking on week ending February 21, 2009. The proportion of ILI visits to ILINet providers ranged from 2.1% to 16.1%, peaking a week later. The weekly ILI proportions for both systems followed similar trends during the influenza season. The response proportion was consistently above 45% each week and as high as 85%. During the novel H1N1 influenza situation trends in ILI proportions mirrored each other in both systems.
Conclusion: MRITS trends closely matched trends in ILINet and laboratory reporting in both seasonal and novel influenza periods. During the novel H1N1 situation, MRITS continued to be a surrogate of more formalized statewide surveillance methods, and could be expanded to other public health surveillance efforts.
David Blythe, MD, MPH, Rene Najera, MT, MPH2, Dale Rohn, MPH2, Lucy Wilson, MD2 and  R. F. Najera, None..
L. Wilson, None..
D. Blythe, None..
D. Rohn, None., (1)Maryland Department of Health and Mental Hygiene, Baltimore, MD