swine flu (generic)

(CNN) - Chinese researchers have discovered a new type of swine flu that can infect humans and has the potential to cause a future pandemic, according to a study released on Monday, though scientists have cautioned that the virus does not pose an immediate global health threat.

The disease, which researchers called the G4 virus, is genetically descended from the H1N1 swine flu that caused a pandemic in 2009. G4 now shows "all the essential hallmarks of a candidate pandemic virus," said the study, published in the scientific journal Proceedings of the National Academy of Sciences (PNAS).

But Dr. Angela Rasmussen, a virologist at Columbia University's public health school, warned the public not to "freak out."

"Our understanding of what is a potential pandemic influenza strain is limited," she posted on Twitter. "Sure, this virus meets a lot of the basic criteria but it's not for sure going to cause a hypothetical 2020 flu pandemic, or even be a dominant strain in humans."

Chinese researchers based at several institutions, including Shandong Agricultural University and the Chinese National Influenza Center, discovered the G4 virus during a pig surveillance program. From 2011 to 2018, they collected more than 30,000 nasal swab samples from pigs in slaughterhouses and veterinary teaching hospitals across 10 Chinese provinces.

From these samples, researchers identified 179 swine influenza viruses -- but not all of them posed a concern. Some only showed up one year out of the program's seven, or eventually declined to nonthreatening levels.

But the G4 virus kept showing up in pigs, year after year -- and even showed sharp increases in the swine population after 2016.

Further tests showed that G4 can infect humans by binding to our cells and receptors, and it can replicate quickly inside our airway cells. And though G4 holds H1N1 genes, people who have received seasonal flu vaccines won't have any immunity.

G4 already appears to have infected humans in China. In Hebei and Shandong provinces, both places with high pig numbers, more than 10% of swine workers on pig farms and 4.4% of the general population tested positive in a survey from 2016 to 2018.

There is no evidence yet that G4 could spread from person to person -- perhaps the most promising sign so far, said Carl Bergstrom, a professor of biology at the University of Washington.

"This is not a *new* new virus; it's been very common in pigs since 2016," he tweeted. "There's no evidence that G4 is circulating in humans, despite five years of extensive exposure. That's the key context to keep in mind."

However, researchers warn in the paper that the virus was on the rise among pig populations, and could "pose a serious threat to human health" if not carefully monitored. Transmission of the virus from pig to human could "lead to severe infection and even death," said the study, which called for greater control of the virus' spread within pig populations.

Surveillance and discovery

In 2009, the H1N1 swine flu pandemic killed an estimated 151,700 to 575,400 people globally. In the aftermath, authorities and scientists stepped up surveillance of pig populations to watch for viruses with "pandemic potential."

Swine flu occurs in people that are in contact with infected pigs. Symptoms are similar to that of regular human influenza and can include fever, lethargy, lack of appetite, coughing, runny nose, sore throat, nausea, vomiting and diarrhea.

After 2009, the H1N1 virus in humans spread back into pigs around the world, and the genes mixed into new combinations -- creating new viruses like G4.

"Pig farming is a massive industry in China and pigs can be important hosts from which novel influenza viruses may emerge," said James Wood, Head of Veterinary Medicine at the University of Cambridge. He added that the study was a "salutary reminder that we are constantly at risk of new emergence of zoonotic pathogens and that farmed animals, with which humans have greater contact than with wildlife, may act as the source for important pandemic viruses."

To decrease the risk of a human pandemic, Chinese farmers and authorities need to control the spread of the virus among pigs, and closely monitor people who work with the animals, said the team.

The new study comes as the world grapples with the Covid-19 pandemic, which has now infected more than 10.3 million people globally and caused more than 505,000 deaths, according to data from Johns Hopkins University.

The central Chinese city of Wuhan is ground zero for the novel coronavirus, which emerged in December last year and began spreading internationally in January. The outbreak prompted China to impose strict lockdowns nationwide, closing local and provincial borders and ordering residents to stay at home.

The country began reopening in March after largely containing the virus -- but new outbreaks and local transmissions in recent weeks have seen some cities go back under lockdown.

© 2020 Cable News Network. Turner Broadcasting System, Inc. All Rights Reserved.

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(5) comments

JaseBo

Its all about the destruction of the US economy in retaliation for the US electing a president that will not bow down to China.

Dan7543

Bwahahahahahaha! We elected the dullest tool in the shed as president. We elected a president that is as bright as a wooden light bulb.

Verdad

The virus is does not care about politics. Try to understand that.

Verdad

Feb. 10, Fox Business interview:

"I think China is very, you know, professionally run in the sense that they have everything under control," Trump said. "I really believe they are going to have it under control fairly soon. You know in April, supposedly, it dies with the hotter weather. And that's a beautiful date to look forward to. But China I can tell you is working very hard."

Feb. 10, campaign rally in Manchester, N.H.:

“I spoke with President Xi, and they’re working very, very hard. And I think it’s all going to work out fine.”

Feb. 13, Fox News interview:

“I think they've handled it professionally and I think they're extremely capable and I think President Xi is extremely capable and I hope that it's going to be resolved."

Feb. 18, remarks before Air Force One departure:

“I think President Xi is working very hard. As you know, I spoke with him recently. He’s working really hard. It’s a tough problem. I think he’s going to do — look, I’ve seen them build hospitals in a short period of time. I really believe he wants to get that done, and he wants to get it done fast. Yes, I think he’s doing it very professionally.”

Feb. 23, remarks before Marine One departure:

"I think President Xi is working very, very hard. I spoke to him. He's working very hard. I think he's doing a very good job. It's a big problem. But President Xi loves his country. He's working very hard to solve the problem, and he will solve the problem. OK?"

Feb. 26, remarks at a business roundtable in New Delhi, India:

“China is working very, very hard. I have spoken to President Xi, and they’re working very hard. And if you know anything about him, I think he’ll be in pretty good shape. They’re — they’ve had a rough patch, and I think right now they have it — it looks like they’re getting it under control more and more. They’re getting it more and more under control.”

Verdad

"NOT BOWING DOWN"

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