The United States plans new rules for the movement of dairy cows between states because of concerns about a bird flu outbreak. 

出于对禽流感爆发的担忧，美国计划对各州之间奶牛的流动制定新规则。

The virus is called Type A H5N1. It has been found in over 30 different groups of cows across eight states. 

该病毒被称为 A 型 H5N1。 已在 8 个州的 30 多个不同的奶牛群中发现了这种病毒。 

Some inactive markers of the virus have been found in milk sold in stores. Inactive markers mean the virus is dead and cannot harm humans who drink the milk. 

在商店出售的牛奶中发现了一些非活性病毒标记。 不活跃的标记意味着病毒已经死亡，不会伤害喝牛奶的人。 

The concern is that the virus could mutate, or change. It could then possibly spread from cows or other animals to humans. Experts, however, believe the risk of that is low. 

令人担忧的是病毒可能会变异或改变。 然后它可能从牛或其他动物传播到人类。 然而，专家认为这种风险很低。 

After April 29, cows must have been tested and found to not have the virus before they are permitted to be moved between states. 

4 月 29 日之后，奶牛必须经过检测并发现没有携带病毒，然后才能获准在各州之间转移。 

The virus has been known by scientists to circulate among wild birds. It appears in other animals if they eat sick birds. Some animals that live near the sea have tested positive for the virus, including harbor seals and polar bears. Animals that eat grasses, such as cows and goats, have only recently been found to have the virus. 

科学家已知该病毒在野生鸟类中传播。 如果其他动物吃了病鸟，也会出现这种情况。 一些生活在海边的动物的病毒检测呈阳性，包括斑海豹和北极熊。 直到最近才发现牛和山羊等吃草的动物携带这种病毒。

Richard Webby is an influenza expert at St. Jude’s Children’s Research Hospital in Tennessee. He said flu viruses are known for adapting to spread among new animals. Finding the virus in dairy milk raises concerns that it could spread to people, Webby said. 

理查德·韦比是田纳西州圣裘德儿童研究医院的流感专家。 他说，众所周知，流感病毒能够适应在新动物之间的传播。 韦比说，在牛奶中发现这种病毒引发了人们对其可能传播给人类的担忧。 

Scientists confirmed the virus in cows in March after farmers said their cows were sick. They said the animals’ symptoms included tiredness and low milk production. Some farmers said the milk the sick cows produced was thick and yellow. 

三月份，在农民表示他们的奶牛生病后，科学家们证实了奶牛体内存在这种病毒。 他们说，这些动物的症状包括疲倦和产奶量低。 一些农民表示，病牛产出的牛奶又浓又黄。 

Matthew Aliota is an animal medicine researcher at the University of Minnesota. He said finding the inactive virus in the milk “suggests this has been going on longer, and is more widespread, than we have previously recognized.” 

马修·阿利奥塔（Matthew Aliota）是明尼苏达大学的动物医学研究员。 他说，在牛奶中发现失活病毒“表明这种情况持续的时间比我们之前认识的要长，而且范围更广。” 

The U.S. Department of Agriculture recently sent out new genetic information about the virus. 

美国农业部最近发布了有关该病毒的新基因信息。 

Michael Worobey is an evolutionary biologist with the University of Arizona. He said the federal agency information makes him think the virus moved from birds to cows late in 2023. 

迈克尔·沃罗贝 (Michael Worobey) 是亚利桑那大学的进化生物学家。 他说，联邦机构的信息让他认为病毒在 2023 年底从鸟类转移到了牛身上。