The effect of influenza-like illness symptoms and laboratory confirmed influenza A on hand hygiene and other health habits among US University students

Abstract

Background: Although hand hygiene and other non-pharmaceutical interventions have been used for mitigating influenza, the effect of influenza illness on adherence with these measures is unknown. Methods: Data analyzed came from a cluster randomized intervention trial held at the University during the 2007-2008 flu season. Immediate and sustained effects on hand hygiene and reduction in social contacts from clinically verified ILI and seasonal influenza A were examined using lagged regression to estimate beta ($) coefficients and 95% confidence intervals. Separate analyses were conducted for comparing (1) clinically verified ILI cases, non-clinically verified ILI cases, and healthy ILI-free controls (no reported ILI either clinically or on surveys); and (2) influenza A cases, clinically verified or survey reported ILI cases not positive or tested for influenza, and healthy ILI-free controls. Clinical ILI and influenza cases were further dichotomized by ILI symptom severity (ss) based on their mean value. Results: During the week of illness verification, clinically verified ILI cases reported washing hands less than participants with non-clinically verified ILI and healthy controls (i.e. nonclinical ILI cases) ($=-1.04, p=0.03; high ss cases vs. low ss/non-clinical ILI cases: $=-1.55, p=0.02; low ss cases vs. high ss/non-clinical ILI cases: $=-0.52, p=0.56). Clinical ILI cases also reported using hand sanitizer more, spending less time handwashing, and spending fewer hours in their own residence hall rooms during the week of illness verification (all p>0.05). Comparing influenza A cases to ILI only cases and controls (i.e. non-flu cases) during the week of viral confirmation, flu cases reported spending fewer hours in their own residence hall rooms ($=-2.56, p=0.01; high ss cases vs. low ss/non-flu cases: $=-3.52, p=0.03; low ss cases vs. high ss/non-flu cases: $=-1.60, p=0.56). However, flu cases reportedly had better hand hygiene than non-flu cases (all p>0.05). No sustained effects were observed. Conclusion: Although adherence to non-pharmaceutical interventions varied by clinical ILI and seasonal influenza A occurrence, the temporal changes were not statistically significant. Emphasis on the importance of complying with non-pharmaceutical recommendations such as hand hygiene and voluntary reduction in social contacts is needed to potentially mitigate disease spread among university students on campus. Abstracts for SupplementInternational Journal of Infectious DiseasesVol. 14Preview Full-Text PDF Open Archive