20 July 2020

Pigs: Mixing pots for influenza

Posted by Shane Hanlon

This is part of a student blog series as part of the University of Pittsburgh’s Disease Ecology Class that our own Shane M Hanlon is currently teaching. Find out more about the series and read all the posts here!   

By Owen Takac

Pigs eating potatoes in Great Livermere, Suffolk. Credit: Wikipedia

I was recently reading an article on Healthline.com that discussed a new form of swine flu that was recently discovered in China.  The new strain is called G4, and it has come to researcher’s attention after being discovered in Chinese pigs.  There was a recent study published in Proceedings of the National Academy of Sciences that presents the findings of a virus surveillance of China’s pigs between 2011 and 2018.  The findings of the study were shocking, presenting evidence that shows that this G4 virus has the potential to start a pandemic.  While it is not currently able spread among humans, it can infect humans, and the researchers responsible for the study of interest believe that it could possibly evolve these abilities.  They advise that we prepare for the worst because transmission is highly variable between pigs and humans, bats and bats, and pigs and bats, which means that it will be hard to determine where and when mutation can occur. 

This study was done by collecting mucus swabs from the noses of pigs between the years given above.  All in all, over 30,000 swabs were collected.  From these swabs, 179 different variations of swine flu were collected.  Of these 179 strains, one strain continuously showed its face year after year: G4.  It contains the features of the influenza virus responsible for the 1918 flu pandemic and some from the recent H1N1 pandemic, all blended into one new virus.  This is due to the fact that a pig can be a sort of vessel for the mixing of viruses, allowing multiple strains to combine to form a new one. 

The largest concern, when it comes to a possible human pandemic, is that humans may not have the same level of defenses to this form of the flu as they do to past forms, as we have never encountered it before.  This is a major issue because if the body cannot clear or limit the infection, viruses will spread very fast.  Due to this, scientists have already began working towards a solution to this virus.  Individuals who have been in contact with G4 infected pigs are under close surveillance, and they have been vaccinated to prevent recombination with other forms of the flu. 

Source: New Swine Flu Discovered in China: Why You Don’t Need to Worry Too Much Yet