JOIN USHere is all you need to know about G4 virus
Researchers have discovered a new strain of influenza among pigs in China that is capable of transmitting to humans and triggering a global pandemic, a study published in the US science journal, Proceedings of the National Academy of Sciences (PNAS), stated.
The virus is named G4 and has genetically descended from the H1N1 strain that caused a pandemic in 2009.
Here is all you need to know about the G4 virus
The G4 virus has become predominant among pigs since 2016. Based on a surveillance in pigs in China from 2011 to 2018, the recent study found that G4 viruses bind to receptor molecules in human cells, and can replicate in the outer layer of the respiratory system.
Authors and scientists at Chinese universities and China’s Center for Disease Control and Prevention say that the strain possesses “all the essential hallmarks of a candidate pandemic virus.”
No evidence of human-to-human transmission yet
Although researchers worry that the virus may already have mutated to pass from animals to humans, there is no evidence that it can be passed from human to human.
Two recent cases of the G4 virus infection reported in 2016 and 2019, had neighbours who reared pigs. The patients were aged 46 and nine-years-old respectively, therefore, suggesting that the G4 virus “could transmit from swine to human, and lead to severe infection and even death.”
“Thus, it is necessary to strengthen the surveillance effort of G4 EA viruses among swine and human populations,” the researchers wrote in the study, pointing out that the virus strain is becoming prevalent among workers in the swine industry.
They added that the widespread circulation of the G4 virus in pigs “inevitably increases their exposure to humans.”
Experiment on ferrets showed severe symptoms
As part of a project to identify potential pandemic influenza strains, nasal swabs from pigs at slaughterhouses in 10 Chinese provinces and 1,000 swabs from pigs with respiratory symptoms seen at their school’s veterinary teaching hospital from 2011 to 2018, were collected.
The results showed 179 swine influenza viruses, out of which the majority were G4 or one of five other G strains from the Eurasian avianlike lineage, reported Hindustan Times.
Various experiments demonstrated that the G4 virus can efficiently infect ferrets, causing severe clinical symptoms in them like sneezing, wheezing, coughing, and weight loss.
Ferrets experience similar symptoms to humans such as fever, coughing and sneezing, and are widely subject to experiments for flu studies.
No immunity against G4 virus
The tests also proved that humans are not protected from the highly infectious G4 virus because of any pre-existing immunity gained from other human influenza vaccine strains. There is no pre-existing population immunity to the virus, the study says.
Blood sample analysis done by the researchers showed that 10.4 per cent of swine workers had already been infected. Reports say that about 4.4 per cent of the general population also appeared to have been exposed.
The study found that the virus is a unique blend of three lineages: one similar to strains found in European and Asian birds, the H1N1 strain that caused the 2009 pandemic, and a North American H1N1 that has genes from avian, human, and pig influenza viruses.
The researchers who led the PNAS study called for strengthened surveillance of Chinese pigs for influenza viruses like the G4 virus and demanded urgent measures to be taken to monitor everyone working with pigs.