Up until 1854, there had been a great deal of theorizing concerning the causes and modes of transmission of diseases.

一直到1854年，出现了大量关于流行病起因及传染方式的推理。

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Mosquito-borne disease, generally there are two modes of transmission: spread of biological and mechanical transmission.

蚊子传播疾病，大致有两种传播方式：生物性传播和机械性传播。

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If we are only arrested and confined to the written historical literature, we will ignore the route and modes of transmission existing.

如果我们仅仅拘囿于历史文献所记，就会忽略那些不为史家所关注而实际上又存在的传播途径和传播方式。

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Today, traditional modes of transmission are threatened by the decreasing number of initiates due to the predominance of urban lifestyles among younger generations, and ritual practices take place less and less regularly.

UNESCO: Intangible Cultural Heritage