contagion          
noun [ U ]  formal uk/kənˈteɪ.dʒən/ us/kənˈteɪ.dʒən/
 接触传染
the situation in which a disease is spread by touching someone or something
  The doctor says there's no chance/danger of contagion. 医生说不存在传染的可能/危险。 
  (情绪、思想、风俗等的)感染,蔓延,传播,扩散
the situation in which feelings, ideas, or problems spread from one place to another
  Brazil's stock markets were battered by contagion from the problems in other emerging markets. 巴西股票市场因为世界上其他新兴市场问题的蔓延而受到了重创。