Influenza
Influenza [2017-02-06]
Originally, the word “influenza” meant that one is being “influenced” by an ominous influence. Influenza is an infectious disease caused by a virus, whose symptoms can be mild to severe.
The most common symptoms of influenza are fever, muscle pain, runny nose, and headache.
Especially, influenza causing a huge number of outbreaks is called a pandemic.
In the 20th century, three influenza pandemics occurred: Spanish Influenza, Asian Influenza, and Hong Kong Influenza.
These caused more than a million deaths.
