Sign up for our free Health Check email to receive special analysis on your health for the week
Receive a free health check email
Humans transmit more viruses to domestic and wild animals than livestock and wild animals can infect, a new study suggests.
Researchers at University College London (UCL) have analyzed all publicly available viral genome sequences to determine where viruses jump from one host and into another vertebrate species (animals with backbones and skeletons). I checked to see if it was infected.
Understanding how and why viruses evolve to jump into different hosts could help experts figure out how new viral diseases arise in humans and animals.
Most infectious diseases are caused by viruses that circulate in animals, and when these infect humans in a process known as zoonotic disease, outbreaks of diseases such as Ebola, influenza, and COVID-19, and contagious diseases. , could cause a pandemic.
Experts say that given the large public health impact of these diseases, humans are generally considered the source of infection rather than the source of the virus, and human-to-animal virus transmission receives less attention. It suggests that it is not.
In a new study, scientists found that host jumps from humans to other animals (known as anthropogenic events) are estimated to be about twice as common as vice versa.
Additionally, many more animal-to-animal host-to-animal jumps were discovered that did not involve humans.
Scientists say their findings highlight the underappreciated fact that human viruses often spread from humans to wild and domestic animals.
Co-author Professor François Ballou, from the UCL Institute of Genetics, said: “Humans should not be considered sources of zoonotic diseases, but just one node in a vast network of hosts with an endless exchange of pathogens.
“In both directions, investigating and monitoring the transmission of viruses between animals and humans can help us better understand their evolution, improve our preparedness for future new disease outbreaks and epidemics, and protect us.” We hope to be able to support these activities as well.”
For this study, the research team developed and applied tools used to analyze approximately 12 million viral genomes in public databases.
They reconstructed the evolutionary history and past host jumps of viruses across 32 virus families and investigated which parts of the viral genome acquired mutations during host jumps.
The study found that, on average, a virus's host jump is associated with increased genetic changes, or mutations, in the virus, and how the virus must adapt to better take advantage of its new host. It was found that it was reflected.
Furthermore, viruses with broader host ranges may have the ability to infect a greater variety of hosts, as viruses that have already infected many different animals have weaker signals for this adaptive process. It is suggested that.
Lead author Cedric Tan, a PhD student at the UCL Institute of Genetics and the Francis Crick Institute, said: 'When animals receive the virus from humans, it harms them and poses a potential threat to the conservation of the species. “Not only that, but it could also lead to new problems.” When large numbers of livestock need to be culled to prevent an outbreak, as has happened in recent years with the H5N1 avian influenza strain, this can impact food security and is also dangerous for humans.
“Furthermore, if a human-borne virus infects a new animal species, the virus may continue to proliferate even if it is eradicated among humans, or it may evolve new adaptations before infecting humans again. It's even possible.
“Understanding how and why viruses evolve to jump into different hosts across the broader tree of life could help us understand how new viral diseases arise in humans and animals. there is.”
The findings are published in the journal Nature Ecology and Evolution.
