The Effect of Mixing Events on the Dynamics of pH1N1 Outbreaks at Small Residential Colleges

Abstract

Objective: The authors examine the dynamics and the impact of all-campus events on pH1N1 spread at Bates College in fall 2009, with comparisons to 3 other campuses. Participants: Students (N = 285) presented or called in to the Bates Health Center with symptoms consistent with influenza-like illness. Methods: Health Center staff at Bates collected data on the outbreak; data from other colleges are from Web sites and journal articles. Data were analyzed using a mathematical model for influenza. Results: Bates held 2 vaccine clinics mid-outbreak. The data are consistent with the hypothesis that the vaccine clinics may have altered routine student interactions, facilitating transmission of pH1N1 among students who otherwise might not have encountered each other. Conclusion: The vaccine clinics, held when vaccine became available, were too late to halt transmission. The disruptions to campus rhythms due to the vaccine clinics may instead have contributed to pH1N1 spread.

Keywords:

• math model
• mixing event
• pH1N1
• residential colleges
• vaccine

ACKNOWLEDGMENTS

We thank our colleagues Lee Abrahamsen, Pamela Baker, and Seri Lowell for helpful discussions. We appreciate the assistance of Will Ash, Bates College Imaging and Computing Center, with graphics and Laurie McConnell and Sylvia Deschaines with manuscript preparation. We received support at Bates from Tedd Goundie, Dean of Students, as well as Christy Tisdale, Director of Health Services.