They detect a new virus in pigs that infects men and has "pandemic capacity"
A group of Chinese scientists has discovered a new type of swine flu that is capable of triggering a pandemic . One more. The new strain recently emerged and is carried by pigs, but they can infect humans. Also, because it is new, people may have little or no immunity to the virus. This is suggested by a study published in the American scientific journal Proceedings of the National Academy of Sciences (PNAS) .
" It has all the essential characteristics of being highly adapted to infect humans, " say the authors, scientists from Chinese universities and the Asian giant's Center for Disease Control and Prevention. Above all, they warn, there is a risk that viruses will pass from animals to humans in China's most populous areas, where millions of people live near farms, slaughterhouses and wet markets that do not pass adequate sanitary controls.
WHAT VIRUS IS IT?
The new study focuses on a flu virus called G4 , which is genetically descended from the H1N1 strain, an old acquaintance that already caused a pandemic in 2009, killing 150,000 to 500,000 people worldwide. The new strain of flu is similar to the swine flu of 11 years ago, but with some changes . According to the report, it also has a unique combination of three lineages: one similar to the 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 influenza viruses, human and swine.
"The G4 variant is especially worrisome because its nucleus is an avian influenza virus, to which humans have no immunity , with fragments of mammalian strains mixed in humans," explained in the scientific journal Science Edward Holmes, a biologist at the University of Sydney studying pathogens.
Between 2011 and 2018, as part of a project to identify possible strains of influenza - contagious respiratory disease - pandemic, a team led by Liu Jinhua of the Chinese Agricultural University (CAU) analyzed about 30,000 nasal swabs taken from pigs in slaughterhouses in 10 Chinese provinces and another 1,000 pig swabs with respiratory symptoms in a veterinary hospital. From these samples, the researchers identified 179 swine influenza viruses , but not all of them were of concern. Some only appeared one year out of the show's seven, or eventually declined to non-threatening levels.
Instead, some farm workers also showed elevated levels of the virus in their blood. In Hebei and Shandong provinces, more than 10% of pig farm employees tested positive in a 2016-2018 survey . Although these documented cases were dead-end infections that were not passed on to others. Therefore, the virus has already passed from animals to humans, but there is still no evidence that it can be transmitted from human to human, the scientists' main concern . Symptoms are similar to those of normal human flu and may include fever, lethargy, poor appetite, cough, runny nose, sore throat, nausea, vomiting, and diarrhea.
The SARS-CoV-2 coronavirus is no exception. It was a probability known to many specialists , who have been warning for several years of the possibilities that an animal virus would jump to humans and cause a pandemic.
A new study has identified another one of these threats. A new influenza virus, present in pigs and already contagious to humans. Only one mutation would be missing that would allow it to be spread not only from animal to person, but also from humans to generate a new risk of a pandemic.
Chinese scientists have identified this respiratory virus, warning that it "meets all the requirements" to adapt to humans. The study, published by the United States National Academy of Sciences , argues that the risk is not imminent, but that the mutations necessary for transmission between people could be a matter of time.
That is why the researchers recommend monitoring the transmission of this new flu virus among pigs and also among farm workers who have already been infected.
As with SARS-CoV-2, humans have not developed immunity against this swine flu. For us it is a new pathogen.
Although in this case, it has great similarities with the swine flu that broke out in Mexico in 2009 . That epidemic was not as deadly as the current one because the similarity of the pathogen with other flu allowed the immune response, especially in the elderly , to be better.
This same biological resemblance would allow the development of a vaccine against this new pathogen if it were necessary in a shorter period of time than those currently considered in the case of the coronavirus.
