contagion

US /kənˈteɪ.dʒən/
UK /kənˈteɪ.dʒən/
"contagion" picture
1.

the communication of disease from one person or organism to another by close contact

:
The rapid spread of the virus highlighted the dangers of contagion.
Strict measures were put in place to prevent further contagion.
2.

the rapid communication of an influence (such as a doctrine or emotion) from one person or place to another

:
The contagion of fear spread quickly through the crowd.
The economic crisis showed the contagion effect across global markets.