As saliva is one of the main vectors of infection and the tuberculosis bacillus can survive in spit for a whole day, spitting was outlawed in numerous countries.

由于唾液是传染的重要媒介，而且结核杆菌能在痰中存活一整天，因此在很多国家，随地吐痰就成为违法行为了。

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West Nile virus (WNV) infection is an endemic disease caused by WNV that is maintained in a natural transmission cycle involving mosquito vectors and bird reservoir hosts.

西尼罗病毒(WNV)感染是一种经蚊虫传播，以鸟类为主要动物宿主的自然疫源性疾病。

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Web exploits and malicious email are two key infection vectors for malware.

FORBES: 8 Steps To Keep Your PCs Safe From Online Criminals

The giant companies that now produce our food have also become potential vectors for mass infection.

ECONOMIST: Food safety