Worker Protection against Influenza - A Pilot Study
Principal Investigator: Werner Ernst Bischoff
Influenza, avian influenza, varicella, and SARS belong not only to the most virulent viruses known to human kind but are also spread by the airborne route. Strategies to prevent and control the often explosive outbreaks associated with these pathogens are limited to vaccination and treatment, if available, or isolation and barrier precautions. The latter includes the utilization of face masks to interrupt the chain of transmission. However, the scientific evidence regarding the efficacy of face masks has been solely based on studies using mannequin heads and non-viable tracers and/or bacteria.
We propose to develop a model for the airborne dispersal of viable viral pathogens (FluMist Influenza vaccine) and for testing the efficacy of barrier precautions such as face masks in human subjects. In the first aim, we will establish a test procedure to disperse particles in a defined size (10 µm) containing preset amounts of Influenza virus. The particle size represents transmission by droplet (10 µm). Dispersal will be measured by a particle counter, and an air sampling method, impaction. In the second aim, the relevance of the trans-ocular route will be determined by exposing the eyes of a participant while he is breathing clean, virus free air through a face mask. The third aim will determine the efficacy of currently recommended barrier precautions, surgical masks and N95 respirators. Participants will be enrolled in intervention groups undergoing exposure to Influenza virus while wearing surgical masks or N 95 respirators.
This project is the first attempt to develop a method for evaluation of the utility and efficacy of face masks using a viable pathogen in human subjects. Furthermore, an improved understanding of the pathology of airborne viruses allows for a better risk assessment of transmission via the airborne route. This knowledge is paramount in view of the current viral pandemics.