noun which may take the genitive case particle 'no', noun
epidemic; prevalent
Medical term used as a noun or no-adjective to describe diseases or phenomena that spread widely. Often appears in compounds like 流行性感冒 (influenza).
流行性の病気が広がっている。
An epidemic disease is spreading.
このウイルスは高い流行性を持っている。
This virus has high epidemic potential.
伝染性 emphasizes contagiousness or infectivity, whereas 流行性 focuses on the widespread, epidemic aspect.
Compound of 流行 (りゅうこう, 'spread, prevalence') and 性 (せい, 'nature, characteristic'), literally 'epidemic nature'.