Influenza Transmission and the Role of Personal Protective Respiratory Equipment: An Assessment of the Evidence
The Expert Panel on Influenza and Personal Protective Respiratory Equipment
Seasonal influenza and its complications send, on average 20,000 Canadians to hospital each year and cause 4,000 deaths. Pandemics occur when a new strain of the influenza virus appears to which humans have little or no pre-existing immunity. This strain usually spreads quickly from person to person across a wide geographical area. Despite the impossibility of predicting where and when the next pandemic might occur or how virulent the virus will be, governments and international bodies must be prepared with plans to help minimize the health, social and economic consequences of such an event.
How and where is influenza (both seasonal and pandemic) transmitted? Based on the conclusions of this review, what is the contribution that N95 respirators or surgical masks will make in the prevention of transmission of influenza?
In 2007, the Public Health Agency of Canada asked the CCA to assess the modes of transmission of influenza and the contribution of respirators or surgical masks in inhibiting the spread of the virus.
The Expert Panel on Influenza and Personal Protective Respiratory Equipment concluded that the current weight of evidence shows that transmission of influenza by inhalation is more probable than by direct contact. The Panel also found that N95 respirators do protect against the inhalation of many types of particles while surgical masks worn by an infected person can also play a role in transmission prevention.
The conclusions of the Panel helped to inform debates about the value of hand hygiene in the 2009 H1N1 epidemic and will continue to be of value to governments at all levels as they develop pandemic preparedness plans.