Non-pharmaceutical public health measures for mitigating the risk and impact of epidemic and pandemic influenza

Influenza pandemics occur at unpredictable intervals, and cause considerable morbidity and mortality. Influenza virus is readily transmissible from person to person, mainly during close contact, and is challenging to control. In the early stage of influenza epidemics and pandemics, there may be delay in the availability of specific vaccines and limited supply of antiviral drugs.

Non-pharmaceutical interventions (NPIs) are the only set of pandemic countermeasures that are readily available at all times and in all countries. The potential impacts of NPIs on an influenza epidemic or pandemic are to delay the introduction of the pandemic virus into a population; delay the height and peak of the epidemic if the epidemic has started; reduce transmission by personal protective or environmental measures; and reduce the total number of infections and hence the total number of severe cases.