Stress, Influenza, and Health Behavior: Implications for Pandemic Influenza and Infection Control.

Abstract

The impact of 2009 pandemic influenza A H1N1 on morbidity and mortality among university-aged adults, and the noted disparities in attack rates in different populations, point to the need for research to identify novel risk factors for explaining variability in susceptibility and disease status in affected populations. Exposure to psychological stress may constitute one such novel risk factor for acquiring influenza infection that has yet to be examined and well understood, particularly in the university setting. Furthermore, simple health behaviors and practices that might be altered due to psychological stress have not been well studied in relation to influenza acquisition. This dissertation utilizes prospective data from the M-Flu study, a randomized intervention trial conducted among students living in residence halls at the University of Michigan during the 2007-2008 flu season, to demonstrate if increased exposure to psychological stress is significantly associated with increased rates of influenza-like illness (ILI), increased rates of naturally acquired influenza A infection, and higher influenza viral load, a potential biomarker of disease severity. This dissertation also explores the behavioral response to circulating seasonal influenza among participants living in this high-risk setting for transmission of infection. The main findings from this work indicate that (1) differential exposure to psychological stress significantly affects the rate of ILI and naturally acquired infection; (2) increased levels of perceived stress are significantly associated with increased levels of viral load among young adults with confirmed influenza; and (3) young adults in this environment seeking clinical verification of their ILI along with laboratory testing report sub-optimal compliance with non-pharmaceutical recommendations for mitigating the spread of influenza. Implications of these findings for pandemic influenza and infection control within the university setting are discussed.