An acute respiratory infection caused by the influenza virus, often seasonal, accompanied by high fever, cough, and general fatigue.
彼女は先週インフルエンザにかかって寝込んだ。
She came down with the flu last week and was bedridden.
毎年冬にインフルエンザの予防接種を受けている。
I get a flu shot every winter.
学校でインフルエンザが流行して、学級閉鎖になった。
Influenza spread at the school and the class was closed.
インフルエンザの主な症状は突然の高熱と全身の倦怠感だ。
The main symptoms of influenza are sudden high fever and general fatigue.