Effectiveness of non-pharmaceutical measures in preventing pediatric influenza: A case-control study

Abstract

Background: Hygiene behavior plays a relevant role in infectious disease transmission. The aim of this study was to evaluate non-pharmaceutical interventions (NPI) in preventing pediatric influenza infections. Methods: Laboratory confirmed influenza cases occurred during 2009-10 and 2010-11 seasons matched by age and date of consultation. NPI (frequency of hand washing, alcohol-based hand sanitizer use and hand washing after touching contaminated surfaces) during seven days prior to onset of symptoms were obtained from parents of cases and controls. Results: Cases presented higher prevalence of underlying conditions such as pneumonia [OR=3.23; 95 % CI: 1.38 - 7.58 p=0.007], asthma [OR=2.45; 95 % CI: 1.17 - 5.14 p=0.02] and having more than 1 risk factor [OR=1.67; 95 % CI: 0.99 - 2.82 p=0.05]. Hand washing more than 5 times per day [aOR=0.62; 95 % CI: 0.39 - 0.99 p=0.04] was the only statistically significant protective factor. When considering two age groups (pre-school age 0-4 yrs and school age 5-17) yrs, only the school age group showed a negative association for influenza infection for both washing more than 5 times per day [aOR=0.47; 95 % CI: 0.22 - 0.99 p=0.04] and hand washing after touching contaminated surfaces [aOR=0.19; 95 % CI: 0.04 - 0.86 p=0.03]. Conclusion: Frequent hand washing should be recommended to prevent influenza infection in the community setting and in special in the school age group.