Face Masks for Preventing Influenza Transmission (GRIPMASK)

a Randomized Controlled Trial Evaluating the Effectiveness and the Safety of Surgical Masks Wared by the Index Patient for Preventing Secondary Transmission of Influenza A in Households

This work aims to measure the effectiveness of face mask worn by a patient with flu to avoid transmission to other persons in the household.

Background. Non pharmaceutical interventions, and in particular the wearing of face masks, could play a role in controlling the transmission of influenza in the early stages of the epidemic. In the French pandemic plan, surgical masks are recommended in contagious patients in wards. The effectiveness of such masks in preventing transmission of influenza A virus is unknown. Our project aims to assess the preventive efficacy and tolerance of surgical mask. The primary objective is to measure the decrease of the number of secondary cases of flu in households where the index case will wear a surgical mask during its period of infectiousness (5 days), compared to households where the index case will not be subject to this intervention. Secondary objectives are: (1) to study the feasibility and tolerance of wearing a mask continuously during the period of viral shedding; (2) virological description of infection spreading among household contacts based on virological collections.

Non sterile surgical mask, high filtration "AEROKYN", type 2 with eardrop Masks will be worn at home by the patient over a period of 5 days following inclusion, whenever a member of the household will attend the same room or in other confined space (eg car), and changed after 3 hours of consecutive use or sooner if they are tor Masks will not be worn: during the night, when the patient is alone in the room. Moreover, for all households, an incentive in nocturnal isolation of index-patient will be recommended

The number of household contacts who will develop within 7 days of the inclusion of the index patient a respiratory syndrome defined by fever> = 37.8 ° C and a cough or a sore throat.

Characterization of viruses isolated (sub-type and sequence of the portion of HA1 gene for haemagglutinin).

Inclusion Criteria: Patient seeking medical advice for: For symptoms less than 48 hours, combining fever> = 37.8 ° C and a cough, during the period of a seasonal influenza epidemic (as defined by the Sentinel network) Older than 5 years And living in a household size between 3 to 8.. The patient is the first case in the household (index patient). The patient has a positive rapid influenza A test. Informed consent. Affiliation to the social security. Exclusion Criteria: When concomitant influenza cases are known in other householders When the patient is suffering from asthma or COPD (ongoing treatment): Hospitalization. Treatment by a neuraminidase inhibitor.

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Canini L, Andreoletti L, Ferrari P, D'Angelo R, Blanchon T, Lemaitre M, Filleul L, Ferry JP, Desmaizieres M, Smadja S, Valleron AJ, Carrat F. Surgical mask to prevent influenza transmission in households: a cluster randomized trial. PLoS One. 2010 Nov 17;5(11):e13998. doi: 10.1371/journal.pone.0013998.