Torner, N., Soldevila, N., Garcia, J., et al. (2015). Effectiveness of Non-Pharmaceutical Measures in Preventing Pediatric Influenza: A Case-Control Study. BMC Public Health. 15(543).
In this case-control study of illnesses during the 2009-10 and 2010-11 seasons, the authors evaluated the effectiveness of frequency of hand washing, alcohol-based hand sanitizer use, and hand washing after touching contaminated surfaces. Hand washing more than five times per day was the only statistically significant protective factor. Among the school-age 5-17 year old group, both hand washing more than five times per day and hand washing after touching contaminated surfaces had a negative association for influenza infection.