The H1N1 virus triggered a pandemic in 2019 that caused between 150,000 and 600,000 deaths in humans. Now Chinese scientists have found a new form of swine flu, which is derived from the H1N1 virus and has the potential to trigger another pandemic. The new virus is known as the influenza A virus genotype G4 reassortant Eurasian avian-like H1N1, or G4 virus for short.
The pathogen was discovered by scientists who analyzed around 30,000 swabs from pigs from ten Chinese provinces between 2011 and 2018. This was done as part of the ongoing surveillance of domestic pigs in China because they can also infect people with diseases. In total, the scientists discovered 179 previously unknown swine flu viruses, most of which belonged to a new species that has been increasingly observed in pigs since 2016.
To analyze the damage potential of the different viruses, the scientists carried out flu studies with ferrets as they show symptoms similar to those of humans. They were able to prove that the G4 virus is highly infectious and causes worse symptoms than the other newly discovered types of swine flu viruses. The study also shows that the G4 virus multiplies rapidly in human cells.
Human to human infections possible?
In order to investigate whether the virus has already infected humans, the scientists tested 338 workers from slaughterhouses after its discovery. 35 (10.4 percent) of the workers tested positive for G4 EA H1N1. In young workers up to the age of 35, it was more than 20 percent. This increased G4 seroprevalence among pig factory workers is worrying. It is also an indication that the virus could continue to adapt to humans and in theory, infections could also spread from person to person.
Risk of a pandemic can hardly be estimated
The coronavirus spread is already at its peak and doesn’t seem to be coming to an end. G4 is also a zoonotic pathogen which means it gets to humans through animals. It is a reminder that we are constantly exposed to the risk of zoonotic pathogens recurring and that livestock with which humans have more contact than wild animals, can serve as a source for important pandemic viruses. It is hard to know whether a pandemic can arise until it is there. The only thing we can do right now is to monitor the situation closely.