The Truth About Influenza and Pigs


Jennifer Shike, FarmJournal's Pork 

June 30, 2020


Mistruths and incorrect information are making headlines about a possible “new pandemic virus” in pigs. A team of Chinese researchers recently reported on their findings for influenza in pigs from 2011 to 2018. The article, published in April, is now circulating in news headlines.


“Any discussion of illness during a global pandemic naturally raises concerns, but it’s important to note this H1N1 is not a new strain of influenza,” says Dave Pyburn, DVM, chief veterinarian for the National Pork Board. “It has been in China’s hog population since before 2016 and has been a predominant strain in Chinese pigs since that time. The science in this paper is sound, but the conclusions and resulting news stories lack important scientific context. We need to make sure that we stick to the scientific truth and not over-sensationalize the findings.”


The truth? Yes, it is a swine virus. Yes, it has the potential to transmit to humans – just like all influenzas can. But experts say there’s no scientific reason to believe that this virus strain in China is any riskier than any other influenza virus. Here are five reasons why Pyburn says there is no reason to panic:


1.    This is not new.


The surveillance of influenza in swine took place from 2011 to 2018, this is not something that was discovered in the last few months. Pyburn says the journal article explains that this “G4” reassortment of this H1N1 influenza has been the predominant strain in China’s swine population since 2016.


“This has been in China for years,” he explains. “They've known about it for some time, which also means the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) have also known about this for a while, and that's important.”


2.    Humans can build antibody against this strain.


According to the journal article, researchers sampled 338 workers from multiple farms in China. Of those 338 workers, 10% of the workers (35 people) had antibody to this particular strain of H1N1 influenza.


“That’s important because it tells you then that we are able to build antibody against this strain,” he says. “The other important piece that I take from this paper is that they do not speak to any human illness attributed in that slaughter plant to this strain. That’s not to say there wouldn't be, but it must not have been profound if there's nothing here to report on as well. So that's good news.”


With no evidence of human-to-human transmission and a 10% prevalence in humans, it would seem to be indicative that human-to-human transmission was not occurring, Pyburn adds.


3.    WHO monitors the most likely influenza viruses to include in annual vaccine ...


4.    USDA monitors influenza in the U.S. swine herd ...


5.    The U.S. pork industry practices high biosecurity to keep disease out ...