Bird flu: Scientists watching migratory birds, seals amid outbreak

Scientists are monitoring migratory birds, cattle and marine mammals across the Americas amid an outbreak of highly pathogenic avian influenza (HPAI) that has infected at least one person.

Last week, a dairy worker in Texas contracted H5N1, a variant of bird flu, from infected cows. This is the second such case in the United States, and the first time that avian influenza has infected cattle.

Cattle cases have been confirmed in a handful of states from Texas to Michigan, but it’s unclear exactly how the virus spreads so effectively within the population. Therefore, scientists and public health officials are closely monitoring potential vectors.

Brian Richards, emerging disease coordinator at the U.S. Geological Survey’s National Wildlife Health Center, said: “If there is evidence to suggest that there will be sustained mammal-to-mammal transmission in the future, We need to think, ‘How do we deal with that?'” This week’s hill.

According to the U.S. Department of Agriculture, avian influenza is already occurring. Detected in over 200 mammals Even in the US alone. Although there are documented cases, Mammal-to-mammal transmission has historically been very rare and limited in scope..

Typically, when bird flu infects any mammal, it’s a “spill-over” event, Richards said. For example, an animal can die from the virus alone after eating an infected dead bird.

However, an epidemic broke out, Marine mammals such as seals and sea lions Also in North America, South America, and other parts of the world.

The main vectors of infection for cattle, seals, sea lions, and other mammals are migratory birds, which “shed” the virus wherever they go.

“Some of these birds migrate south to South America, where we’ve seen spillover from wild birds to mammals, and even to penguins in Antarctica,” Richards said. .

The Richards said most new avian influenza infections in mammals result from exposure to infected wild birds such as geese, agrackles, gulls and ducks.

“The poultry industry has learned a lot about biosecurity, and the dairy industry could learn too,” Richards said, because while infections in cattle are unprecedented, infections in poultry facilities are unprecedented. Ta.

Infections in mammals such as cows and seals likely came from infected birds, but it’s difficult to explain the amount of infection without mammal-to-mammal transmission, Richards said.

The virus’s capabilities are “an open question,” but the scientific community is “not ready to be alarmed,” he said.

“[It’s] It is not at all implausible that the affected adults were affected. [are eating dead birds] As a very convenient snack. But when you’re talking, [their offspring] “We have to wonder how they got infected when they weren’t old enough to eat dead birds,” he says.

Richards said the cattle’s high-density living conditions could justify a similar measure to the 2 million infected chicken “population reduction” ordered last week by the Texas Department of Agriculture.

“At least for now, the data does not suggest that the situation is progressing rapidly. The data is incomplete at this time and we need to continue to monitor it,” Richards said.

The Centers for Disease Control and Prevention on Friday asked state public health officials to develop rapid response plans for testing and treatment if more human cases occur.