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II. Abstract
The route of transmission of healthcare associated infections is not always well defined.
The airborne dissemination of influenza virus, norovirus and respiratory syncytial virus has
to be assessed. This thesis presents methodologies to detect airborne viruses and some
innovative way to assess their resistance through the airborne route. Two sampling
techniques were used, more precisely a dry sampling using a NIOSH 251 impactor and a
liquid sampling using a Corriolis µ®. Viral cDNA was detected by real-time PCR. To
assess the resistance of norovirus through the air route we used a cultivable experimental
model; the murine norovirus. This thesis presents the first detection of airborne norovirus in
a healthcare setting. Influenza virus was detected in the air of an emergency department and
in the room of influenza positive patient. Respiratory syncytial virus could not be detected
in an airborne state. Pathogenic virus can be disseminated through the airborne route and
could represent an infectious risk.