600 Million Year Evolution of the Common Flu: Tracing its Origins to Fish
Scientists have found evidence of the origin of influenza – a fish that lived 600 million years ago.
A team from the University of Sydney searched the fish genetic database for a virus associated with influenza and found the virus in the gut of the Siberian sturgeon.
By comparing the genetic sequence of the sturgeon virus with all known influenza viruses, the team found that it closely matched the predicted ancestor sequence of these viruses.
The study, which has not yet been peer-reviewed, indicates that a family of influenza viruses that infect humans first appeared in aquatic animals.
The team noticed that the virus in the sturgeon doesn’t have the same original form, it’s “what you would expect from a true ancestral form,” lead author Mary Petrone told New Scientist.
Petron suggested that the flu started at sea due to earlier work in 2018 that found hagfish could contract it.
Mixins are eel-like marine animals that produce mucus.
Using a flu-like hagfish virus, Petrone and her team found that the sturgeon virus was 25 percent genetically similar to its ancestor.
“Understanding the evolution of the influenza virus is really important because it could provide new insights into its ability to move between hosts and help discover the next virus that could become a pandemic,” Petrone said.
The study comes at a time when the world is watching the spread of bird flu in Cambodia.
In its current form, the strain is unlikely to cause a significant outbreak. Broad transmission requires a mutation that allows it to bind to a receptor found on cells in the nose.
However, the H5N1 virus has been found to have evolved to infect humans.
Last week, an 11-year-old girl from Preyveng became the first victim of the H5N1 virus in 2023.
Her father also tested positive for the virus but showed no symptoms.
Dr. Eric Carlson, who led the team at the Pasteur Institute in Cambodia that deciphered the genetic sequence of the girl’s virus, warned that it was different from the bird’s.
He said: “There are some indications that this virus has been transmitted to humans. Once these viruses get to a new host, they go through some changes that allow them to replicate a little better, or potentially bind a little better to the cells of the respiratory system. .”
But he added that the virus has not yet fully adapted to humans, saying it is “mostly an avian virus.”
Source: Daily Mail