Effectiveness of hand hygiene and provision of information in preventing influenza cases requiring hospitalization

Abstract Background The objective of the study was to investigate the effectiveness of non-pharmacological interventions in preventing cases of influenza requiring hospitalization. Methods We performed a multicenter case-control study in 36 hospitals, in 2010 in Spain. Hospitalized influenza cases confirmed by reverse-transcription polymerase chain reaction and three matched controls (two hospital and one community control) per case were selected. The use of non-pharmacological measures seven days before the onset of symptoms (frequency of hand washing, use of alcohol-based hand sanitizers and handwashing after touching contaminated surfaces) was collected. Results We studied 813 cases hospitalized for influenza and 2274 controls. The frequency of hand washing 5-10 times (adjusted odds ratio [aOR] = 0.65) and > 10 times (aOR = 0.59) and handwashing after contact with contaminated surfaces (aOR = 0.65) were protective factors and were dose-responsive (p < 0.001). Alcohol-based hand sanitizers were associated with marginal benefits (aOR = 0.82). Conclusions Frequent handwashing should be recommended to prevent influenza cases requiring hospitalization.