Evaluating Georgetown University's 2009 H1N1 Influenza Syndromic Surveillance System

Background

To provide timely information on the impact of the 2009 H1N1 influenza epidemic from 8/28/2009 to 4/10/2010, Georgetown University developed and implemented a syndromic surveillance system incorporating a variety of data sources.

Research Aims

• Describe the 2009 H1N1 outbreak at an urban university in Fall 2009.

• Identify the datasets those most accurately depict the 2009 H1N1 epidemic in near real-time.

Data and methods The Georgetown data include student influenza-like-illness (ILI) and absenteeism reported to medical and non-medical staff, and employee absenteeism data available in near real-time and retrospectively. As a point of comparison, we also analyzed the George Washington University (GWU) student ILI cases, American College Health Association's Pandemic Influenza Surveillance Network (ACHA) and CDC ILINet data, and performed a contextual analysis of H1N1-related university broadcast and on-campus media reports.

Results

• ILI cases reported to medical staff, especially Emergency Department visits, peaked first in early September and dropped sharply afterwards. This corresponds to GWU records and ACHA data, but not regional ILINet data.

• Retrospective employee absenteeism patterns are similar to those of the previous year.

• Student self reports exhibited a second peak in around mid-term weeks.

Conclusion

Syndromic surveillance systems can be affected by factors that influence people's reporting behavior including communication and intervention policies, incentives and barriers associated with presenting oneself to the reporting system. If these biases are understood and taken into account, these systems can provide useful situational awareness information to university policy makers and medical providers.