What is H1N1 influenza?

Pandemic influenza is caused by the emergence of influenza viruses that are antigenically different from seasonal influenza viruses. It is a disease that occurs when avian and animal influenza viruses, which previously did not infect humans, change so that they can be transmitted efficiently from person to person. New strains of influenza vary greatly in their infectivity and pathogenicity depending on the subtype of the virus. Since most people have not acquired immunity to the new virus, there are concerns that it will become a global epidemic (pandemic) and cause serious health problems. In the past, new strains of influenza have occurred in cycles of 10 to 40 years. In 2009, there was an epidemic originating from swine flu, which was called a new strain of influenza. In 2011, we moved to seasonal influenza.

Main infection prevention measures

The route of infection of new strains of influenza is the same as that of regular seasonal influenza, and is assumed to be mainly “droplet infection (Note 1)” and “contact infection (Note 2)”. Hand washing and cough etiquette are said to be effective for its prevention.
(Note 1) Droplet infection: When an infected person coughs or sneezes, droplets containing the excreted virus (water droplets of 5 microns or more) are scattered, and when inhaled through the nose or mouth, droplets containing the virus are transmitted. It refers to the route of infection through contact with mucous membranes.
(Note 2) Contact infection: This refers to the route of infection through direct contact between the skin and mucous membranes/wounds or indirect contact through an intermediate.

How to wash your hands correctly

• wash your hands (External link)

cough etiquette

• cough etiquette (External link)

In preparation for the outbreak of new influenza (Government Public Relations Online)

• In preparation for the outbreak of new influenza (Government Public Relations Online) (External link)

Countermeasures against new strains of influenza (Bureau of Social Welfare and Public Health, Tokyo Metropolitan Government)

• Countermeasures against new strains of influenza (Bureau of Social Welfare and Public Health, Tokyo Metropolitan Government) (External link)

Itabashi Ward, Tokyo Metropolitan Government Action Plan for Countermeasures against Pandemic Influenza

• Itabashi-ku, Tokyo devised countermeasure action plan for new strains of influenza