contagion

 
Pronunciation: /kənˈteɪdʒ(ə)n/

noun

[mass noun]
  • the communication of disease from one person or organism to another by close contact: the rooms held no risk of contagion
  • [count noun] dated a disease spread by close contact: through personal hygiene the spread of common contagions is discouraged
  • figurative the spreading of a harmful idea or theory: the contagion of disgrace [count noun]: a political fear, a contagion that spread from city to city

Origin:

late Middle English (denoting a contagious disease): from Latin contagio(n-), from con- 'together with' + the base of tangere 'to touch'