Researchers say a new influenza virus found in Chinese pigs has become more infectious to human beings. They said that the new virus needs to be watched closely should it ever leave China and develop into a possible “pandemic virus.”
Health experts said the flu virus does not present an immediate threat to humans, however.
A team of Chinese researchers studied pigs from 10 provinces and in a veterinary hospital. The team studied tests of the animals and said they found a total of 179 swine flu viruses.
The researchers expressed concern about a virus they called “G4.” It is a version of H1N1, the virus that caused a pandemic in 2009.
“G4 viruses have all the essential hallmarks of a candidate pandemic virus,” the researchers noted in a paper published on Monday. It appeared on the website of the U.S. publication Proceedings of the National Academy of Sciences (PNAS).
The researchers called for urgent measures to closely monitor people working with pigs. They noted that pig farm workers in the 10 provinces also showed high levels of the virus in their blood.
Blood tests in the study showed that more than 10 percent of people working with pigs had already been infected. And more than 4 percent of the general population appeared to have been exposed.
The study found that the G4 version of the virus has already passed from animals to humans and the immunity people get from exposure to seasonal flu did not protect them from G4. But there is no evidence that the virus can be passed from person to person.
"It is of concern that human infection of G4 virus will further human adaptation and increase the risk of a human pandemic," the researchers wrote.
Carl Bergstrom, a biologist at the University of Washington, wrote about the study. “There’s no evidence that G4 is circulating in humans, despite five years of extensive exposure. That’s the key concept to keep in mind,” he noted on Twitter.
Bergstrom added that the G4 virus is not “new” and has been in pigs since 2016. He added that the study followed a small group of people in China, and not a larger population.
An official with the World Health Organization (WHO), Christian Lindmeier, said Tuesday that WHO officials will read the Chinese study carefully. He added, “It also highlights we cannot let our guard down on influenza and need to be vigilant and continue surveillance even in the coronavirus pandemic.”
In China, a Foreign Ministry spokesman said that China was closely following developments. “We will take all necessary measures to prevent the spread and outbreak of any virus,” he said.
In 2009, the H1N1 flu virus was discovered first in the United States and spread quickly around the world. The U.S. Centers for Disease Control and Prevention estimated that 60.8 million people were infected with 12,469 deaths nationwide.
The novel coronavirus is believed to have come from bats and people infected at a seafood market in Wuhan, China. By June 30, Johns Hopkins University’s Coronavirus Resource Center reported the virus has infected more than 10.4 million people worldwide. And about 510,000 people have died from COVID-19, the disease caused by the virus.
I'm Jonathan Evans.
Hai Do adapted this story for Learning English based on reports from Agence France Press, Reuters and PNAS. George Grow was the editor.
Words in This Story
pandemic - n. an occurrence in which a disease spreads quickly and affects large number of people around the world
veterinary - adj. relating to medical care and treatment of animals
hallmark - n. quality that is typical of a particular person or thing
monitor - v. to watch, observe
expose - v. to cause someone to experience something
immunity - n. the power to keep yourself from being affected by a disease
adaptation - n. a change that makes it able to live in a particular situation
highlight - v. make people notice or aware of something
vigilant - adj. carefully noticing problems or signs of danger
surveillance - n. the act of carefully watching someone or something