Index Entries

Laetitia Canini, Laurent Andréoletti, Pascal Ferrari, Romina D'Angelo, Thierry Blanchon, Magali Lemaitre, Laurent Filleul, Jean-Pierre Ferry, Michel Desmaizieres, Serge Smadja, Alain-Jacques Valleron, and Fabrice Carrat
November 17, 2010
PLoS One

"Methods

Population description, eligibility and enrollment: We conducted a cluster-randomized controlled trial in which households were randomly allocated to a surgical mask arm (intervention) or a control (non-intervention) arm. The mask had to be worn by the index case only. The intervention was targeted at the household level, and the outcomes were measured at the individual level in household subjects... 

Intervention: … The main objective was to assess the decrease of secondary [influenza-like] illness in household contact in the mask group vs. the control group. We also focused on the tolerance and feasibility of wearing masks...

Discussion

We did not show any significant difference in ILI [influenza-like illness] proportion among household contacts between the intervention arm and the control arm... 

The analysis of other trials testing the efficacy of facemasks use in households did not show a significant decrease of the secondary illness rate in their primary intent-to-treat analyses... [In] this study, no additional benefit was observed when facemask was added to hand hygiene by comparison with hand hygiene alone. Our findings are consistent with these results, suggesting a low effectiveness, if any, of facemasks when used alone to limit influenza transmission in a closed-setting."

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masks