International Scientific Forum on Home Hygiene

Home Hygiene & Health

The Leading Source of Scientific, Professional & Consumer Information
International Scientific Forum on Home Hygiene

Home Hygiene & Health

The Leading Source of Scientific, Professional & Consumer Information

Quantifying the Routes of Transmission for Pandemic Influenza.

This study to quantifies the routes of transmission for this disease. A mathematical model of aerosol (i.e., droplet-nuclei) and contact transmission of influenza within a household containing one infected was constructed. An analysis of this model in conjunction with influenza and rhinovirus data suggests that aerosol transmission is far more dominant than contact transmission for influenza. We also consider a separate model of a close expiratory event, and find that a close cough is unlikely (?1% probability) to generate traditional droplet transmission (i.e., direct deposition on the mucous membranes), although a close, unprotected and horizontally-directed sneeze is potent enough to cause droplet transmission. There are insufficient data on the frequency of close expiratory events to assess the relative importance of aerosol transmission and droplet transmission, leaving open the possibility that droplet transmission is important until proven otherwise. However, the rarity of close, unprotected and horizontally-directed sneezes—coupled with the evidence of significant aerosol and contact transmission for rhinovirus and our comparison of hazard rates for rhinovirus and influenza—leads the authors to suspect that aerosol transmission is the dominant mode of transmission for influenza. Bulletin of Mathematical Biology. 2008;70:820-67.