In nightmarish proportions, a common bedbug appears poised for a blood meal, compliments of a human host.

一只有着噩梦般形状的普通臭虫正准备开始一顿鲜血大餐，向人类主人表示致意。

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The intensity of transmission depends on factors related to the parasite, the vector, the human host, and the environment.

传播严重程度取决于寄生虫、病媒、人类宿主和环境等有关因素。

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They will also collaborate with researchers at the University of California in San Diego to study other pathogens that require a human host, such as malaria.

他们还将和美国加州大学圣地亚哥分校的研究者们合作研究别的需要人类当宿主的疾病，如疟疾。

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Although few pathogens can survive in both an animal and a human host, there is laboratory evidence that resistance can be passed across the species barrier through meat products.

BBC: Animals and antibiotics: the risks

MalariaControl.net can handle a lot of different sorts of variable, from the changing density of parasites within a human host as an infection progresses to the sort of treatment available in different places around the continent.

ECONOMIST: Linking up computers to defeat malaria

Economic conditions create springboards for changes in a host of human behaviors.

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