[ti:COVID Fight Moves to the Wild] [by:www.51voa.com] [00:00.00]更多听力请访问51VOA.COM [00:00.04]Researchers around the world are trying to find out [00:04.12]how much and where COVID-19 is spreading in the wild. [00:10.32]For researcher Todd Kautz and his team [00:13.88]that means giving COVID tests to animals [00:17.40]like bears, moose, deer and wolves. [00:21.60]They are doing their research on a Native American reservation [00:25.64]in the north woods of Grand Portage, Minnesota, close to Canada. [00:32.64]Scientists are concerned that the virus [00:35.88]could change within animal populations. [00:39.24]That could possibly create dangerous new viral mutations [00:43.64]that could jump back to humans and spread among people. [00:48.68]The pandemic has shown that the health of humans and animals is closely related. [00:55.60]Exactly how the virus started has never been proven. [00:59.64]But many scientists say it likely jumped from bats to humans. [01:05.68]Now the virus has been confirmed in wildlife [01:08.64]in 24 states in the United States, including Minnesota. [01:14.20]Recently, a Canadian study showed someone in nearby Ontario [01:19.60]likely got a highly mutated form of the virus from a deer. [01:25.32]"If the virus can establish itself in a wild animal reservoir, [01:29.80]it will always be out there with the threat to spill back [01:33.52]into the human population," said Matthew Aliota. [01:38.68]He is a researcher with the University of Minnesota [01:42.40]working with the Grand Portage Reservation team. [01:46.68]E.J. Isaac is a fish and wildlife scientist. [01:50.96]He said the risk of the virus mutating grows with the start of spring, [01:56.24]when bears wake from hibernation [01:59.04]and deer and wolves move to different areas. [02:02.60]He said more movement among animals [02:05.40]increases the chance of transmission. [02:08.96]The team's research carries its own set of risks. [02:12.56]Sometimes they must capture animals from the air, using a helicopter. [02:18.80]They target animals like deer and moose from the air with a net gun. [02:24.52]Researchers then test the animal's nose for COVID, [02:28.08]and put a tracking device on it. [02:31.24]Another time, Kautz had to enter a bear's den [02:34.60]while it was hibernating in order to test it. [02:37.44]After testing the bear, Kautz sent the samples to a lab. [02:42.68]He hopes to learn not just which animals are getting infected, [02:46.96]but also whether certain animals [02:49.60]are more likely to spread the virus to other species. [02:54.04]Close contact between humans and animals [02:57.40]has permitted the virus to defeat barriers to spread between species. [03:03.60]To infect any living thing, the virus must get into its cells, [03:08.52]which is not always easy. [03:10.68]Virus expert David O'Connor [03:13.64]compares the process to opening a "lock" [03:16.32]with the virus' spike protein "key." [03:19.64]"Different species have different-looking locks, [03:23.24]and some of those locks" are not going to be openable by the key, [03:27.76]the University of Wisconsin-Madison scientist said. [03:32.68]But other locks are similar enough for the virus [03:35.96]to enter an animal's cells and make copies of itself. [03:40.76]As it does, it can mutate and still have a key [03:44.64]that fits in the human lock. [03:46.96]That permits it to go back to humans through close contact [03:50.76]with live animals, scientists believe. [03:54.44]It is rare for a virus to spread from animals to humans. [03:58.56]But it only takes one person to bring a mutated virus to the world of humans. [04:04.20]Some scientists think the Omicron variant of the coronavirus [04:08.92]came from an animal rather than a human. [04:13.08]What scientists are mostly concerned about [04:15.84]is variants spreading widely within a species [04:18.84]that comes in contact with humans, like deer. [04:22.96]Scientists found the coronavirus in a third of deer [04:26.84]tested in Iowa between September 2020 and January 2021. [04:32.92]Other studies found virus antibodies in a third of deer [04:37.88]tested in Illinois, Michigan, New York and Pennsylvania. [04:43.64]I'm Dan Novak. [04:44.76]更多听力请访问51VOA.COM