Worobey said the virus likely spreads among the cows due to contact with milking machines, trucks or the shoes of farm workers. It then moves from cow to cow before making its way back to birds. Worobey said birds tested on the same farms as sick cows have a form of the virus with “clear mammalian adaptations.” In other words, the virus shows signs of changing before infecting the bird populations. 

沃罗比说，由于接触挤奶机、卡车或农场工人的鞋子，病毒可能在奶牛之间传播。然后它从一头牛转移到另一头牛，最后又回到鸟类身上。沃罗比说，在与病牛相同的农场进行测试的鸟类携带了一种具有“明显的哺乳动物适应性”的病毒。换句话说，病毒在感染鸟类之前就表现出了变化的迹象。 

Scientists say the best way to keep the virus from spreading to more cows, and possibly humans, is to test cows as often as possible and follow their movements. 

科学家表示，防止病毒传播给更多奶牛（甚至可能是人类）的最佳方法是尽可能频繁地对奶牛进行检测并跟踪它们的活动。 

Thomas Friedrich is a virology expert at the University of Wisconsin’s animal medical school. “We need to be able to do greater surveillance so that we know what’s going on.” 

托马斯·弗里德里希是威斯康星大学动物医学院的病毒学专家。“我们需要能够进行更大规模的监视，以便我们知道发生了什么。” 

Worobey said testing for active virus is one thing. But the tests must also look for antibodies, or evidence of past infections.

沃罗贝说，检测活性病毒是一回事。但测试还必须寻找抗体或过去感染的证据。 

“That is a really accessible and quick way to find out how widespread this is,” he said. 

他说：“这是了解这种情况有多普遍的一种非常容易且快速的方法。” 

Scientists are working to be sure that heating up the milk before it is put into containers for humans to drink is enough to kill the virus. The process is called pasteurization. The U.S. Food and Drug Administration (FDA) will have more information about that soon. 

科学家们正在努力确保在将牛奶放入容器供人类饮用之前将其加热足以杀死病毒。该过程称为巴氏灭菌。美国食品和药物管理局 (FDA) 将很快提供更多相关信息。 

Right now, the FDA recommends humans to avoid raw or unpasteurized milk. Farm workers are also being told to wear masks, wash their hands and change their work clothes often, Aliota said. 

目前，美国食品和药物管理局建议人们避免食用生牛奶或未经高温消毒的牛奶。阿利奥塔说，农场工人还被告知要戴口罩、勤洗手并经常更换工作服。 

The U.S. Centers for Disease Control and Prevention said 23 people have been tested for the virus so far. One person has tested positive for a mild eye infection. CDC officials are watching for signs of sickness in 44 other people who were in contact with infected animals. 

美国疾病控制与预防中心表示，迄今为止已有 23 人接受了病毒检测。一名患者轻度眼部感染检测呈阳性。CDC 官员正在观察另外 44 名接触过受感染动物的人是否有生病迹象。 

David O’Connor is a virus expert at the University of Wisconsin-Madison. He said that knowing about the virus should not make humans “change anything about how (they) live their daily lives.” 

大卫·奥康纳是威斯康星大学麦迪逊分校的病毒专家。他说，了解这种病毒不应让人类“改变他们的日常生活方式”。 

But he said humans should have “increased awareness that something is happening.” 

但他表示，人类应该“提高对正在发生的事情的认识”。