Bird Flu Spread Increasing, Killing South American Wildlife
2024-03-18
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1The deadly H5N1 bird flu virus is spreading more aggressively than ever before since its arrival in South America in 2022.
2It is killing wild birds and marine mammals on the continent.
3Reuters recently spoke to eight experts in bird flu science.
4All said the current spread raises the risk of the virus becoming a bigger threat to humans.
5The more immediate concern is that the disease, which once affected mostly birdlife, appears to be spreading between mammals.
6The disease has already killed several dolphins in Chile and Peru.
7It has also killed about 50,000 seals and sea lions along the coasts and at least half a million birds across South America.
8Scientists have not yet tested infections in living animals to confirm mammal-to-mammal passage of the virus.
9But they believe it is very likely.
10"It's almost certainly happened," said Richard Webby.
11He is a virologist at St. Jude's Children's Research Hospital in Memphis, Tennessee.
12"It's pretty hard to explain some of these large infections and die off without having mammal-to-mammal spread."
13The same version of the virus has appeared in many bird species.
14Among them are migrating species, scientists told Reuters.
15As climate change continues, animals are forced to move into new territories, often mixing with animals -- and viruses -- that are new to them.
16"It's a matter of time before you will detect the first South American strain in North America," said Alonzo Alfaro-Nunez, a viral ecologist at the University of Copenhagen in Denmark.
17The growing concern led the intergovernmental Pan American Health Organization (PAHO) to gather health experts and officials for a meeting this week in Rio de Janeiro, Brazil.
18The group plans to launch the world's first regional program to supervise bird flu spread.
19The program will run observation and response efforts, a PAHO official told Reuters.
20Since the virus was first detected in Colombia in October 2022, there have been two known cases in humans on the continent.
21One was in Ecuador. The other was in Chile. Birds passed the virus in each case.
22The patients survived. But often, H5N1 kills. About 60 percent of human cases of the virus end in death.
23The World Health Organization is unlikely to raise the H5N1 risk level for humans from the current "low" right now.
24The experts would require evidence of human-to-human transmission or signs of viral changes that would target humans, experts said.
25Several drugmakers have said they are developing bird flu vaccines for humans.
26"We're seeing (the virus) do... little evolutionary steps that are on the long-term moving towards a potential human infection," said Ralph Vanstreels.
27He is a researcher at the University of California, Davis. He is studying South American variants of H5N1.
28With health officials and experts meeting in Rio this week, Latin American countries will be pressured to increase disease surveillance in the wild.
29The region's data is lacking and limited resources have left scientists struggling to understand how the disease is spreading in the wild.
30Scientists expect the number of cases is probably much higher than reported. Some cases are not getting laboratory testing.
31Bolivia, for example, did not register a case in the wild last year.
32But the disease has been reported in surrounding countries, said Manuel Jose Sanchez Vazquez, a disease expert for PAHO's animal health center.
33Overseeing the disease response can also be complex, Sanchez noted. Public health officials deal with threats to humans.
34Agricultural experts and veterinarians deal with health threats to farm animals, including birds, cows and pigs.
35But for wild animal health, care and supervision is provided mostly by environmental officials.
36The new regional commission is expected to be announced on Thursday.
37The group would aim to set methods for observing, treating and reporting cases among government agencies.
38It could also help in sharing laboratory resources.
39"We are worried and we are vigilant," Sanchez said.
40"The more adaptation of the virus to mammals, the more likely it is that transmission to humans could happen."
41I'm Caty Weaver.
1The deadly H5N1 bird flu virus is spreading more aggressively than ever before since its arrival in South America in 2022. It is killing wild birds and marine mammals on the continent. 2Reuters recently spoke to eight experts in bird flu science. All said the current spread raises the risk of the virus becoming a bigger threat to humans. 3The more immediate concern is that the disease, which once affected mostly birdlife, appears to be spreading between mammals. 4The disease has already killed several dolphins in Chile and Peru. It has also killed about 50,000 seals and sea lions along the coasts and at least half a million birds across South America. 5Scientists have not yet tested infections in living animals to confirm mammal-to-mammal passage of the virus. But they believe it is very likely. 6"It's almost certainly happened," said Richard Webby. He is a virologist at St. Jude's Children's Research Hospital in Memphis, Tennessee. "It's pretty hard to explain some of these large infections and die off without having mammal-to-mammal spread." 7The same version of the virus has appeared in many bird species. Among them are migrating species, scientists told Reuters. 8As climate change continues, animals are forced to move into new territories, often mixing with animals -- and viruses -- that are new to them. 9"It's a matter of time before you will detect the first South American strain in North America," said Alonzo Alfaro-Nunez, a viral ecologist at the University of Copenhagen in Denmark. 10Human risk 11The growing concern led the intergovernmental Pan American Health Organization (PAHO) to gather health experts and officials for a meeting this week in Rio de Janeiro, Brazil. 12The group plans to launch the world's first regional program to supervise bird flu spread. The program will run observation and response efforts, a PAHO official told Reuters. 13Since the virus was first detected in Colombia in October 2022, there have been two known cases in humans on the continent. One was in Ecuador. The other was in Chile. Birds passed the virus in each case. 14The patients survived. But often, H5N1 kills. About 60 percent of human cases of the virus end in death. 15The World Health Organization is unlikely to raise the H5N1 risk level for humans from the current "low" right now. The experts would require evidence of human-to-human transmission or signs of viral changes that would target humans, experts said. 16Several drugmakers have said they are developing bird flu vaccines for humans. 17"We're seeing (the virus) do... little evolutionary steps that are on the long-term moving towards a potential human infection," said Ralph Vanstreels. He is a researcher at the University of California, Davis. He is studying South American variants of H5N1. 18Regional response 19With health officials and experts meeting in Rio this week, Latin American countries will be pressured to increase disease surveillance in the wild. 20The region's data is lacking and limited resources have left scientists struggling to understand how the disease is spreading in the wild. Scientists expect the number of cases is probably much higher than reported. Some cases are not getting laboratory testing. 21Bolivia, for example, did not register a case in the wild last year. But the disease has been reported in surrounding countries, said Manuel Jose Sanchez Vazquez, a disease expert for PAHO's animal health center. 22Overseeing the disease response can also be complex, Sanchez noted. Public health officials deal with threats to humans. Agricultural experts and veterinarians deal with health threats to farm animals, including birds, cows and pigs. But for wild animal health, care and supervision is provided mostly by environmental officials. 23The new regional commission is expected to be announced on Thursday. The group would aim to set methods for observing, treating and reporting cases among government agencies. It could also help in sharing laboratory resources. 24"We are worried and we are vigilant," Sanchez said. "The more adaptation of the virus to mammals, the more likely it is that transmission to humans could happen." 25I'm Caty Weaver. 26Caty Weaver adapted this story for VOA Learning English based on reporting by Reuters. 27_______________________________________ 28Words in This Story 29detect - v. to discover or determine the existence, presence, or fact of 30region - n. an administrative area, division, or district 31response - n. an act or instance of replying; answer 32evolution - n. a process of change in a certain direction 33potential - adj. existing in possibility : capable of development into actuality 34vigilant - adj. alert to signs of danger 35adaptation - n. modification of an organism or its parts that makes it more fit for existence under the conditions of its environment 36veterinarian - n. a medical doctor of animals