他们在研究过的三个案例中发现西尼罗河热在美国的的流行与鸟类种群密度的下降相关。

Three of the cases they studied found that the rise of West Nile virus in the U.S. corresponded to decreases in bird population density.

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西尼罗河病毒感染可以为无症状感染(没有症状)，约占受感染人群的80%，也可能导致西尼罗热或严重的西尼罗河疾病。

Infection with WNV is either asymptomatic (no symptoms) in around 80% of infected people, or can lead to West Nile fever or severe West Nile disease.

youdao

西尼罗河病毒感染可以为无症状感染(没有症状)，约占受感染人群的80%，也可能导致西尼罗热或严重的西尼罗河疾病。

Infection with WNV is either asymptomatic (no symptoms) in around 80% of infected people, or can lead to West Nile fever or severe West Nile disease.

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