Experts have raised the alarm over a flu variant that could jump between animals and humans in a shockingly similar way to Covid-19. The Influenza D virus (IDV) was found in China and could “silently” spread to other countries, researchers from Changchun Veterinary Research Institute warned. Led by Hongbo Bao, they said the “newly emerging” strain was showing “alarming exposure rates”.
It has mainly affected cattle, but the researchers said it could have changed from an animal-only pathogen to being able to spread among humans. They wrote: “Our findings indicate that IDV may have acquired the capacity for human-to-human transmission during its ongoing evolution, and currently circulating IDV strains already pose a potential panzootic [the animal equivalent of a human pandemic threat.”
IDV was first discovered in Oklahoma in 2011 when a pig was found with flu-like symptoms, but has now been detected in Europe, North and South America, Asia and Africa.
It has since spread to cattle, which have become the main carriers, potentially posing a risk to cattle workers. Goats, sheep, horses, camels, and dogs have also been affected.
The researchers added: “In recent years, IDV often arrives silently in a new country or continent and does not display symptoms… this raises concerns about whether IDV has acquired enhanced infectivity and transmissibility.”
The experts studied how the strain was found in cattle in Northeastern China in 2023, testing its ability to replicate itself and how infectious it was. They discovered it could spread through the air as well as direct contact between animals.
They concluded: “In summary, it is likely that IDV outbreak has metastasised into an ongoing problem for cattle and humans.
“Unobserved subclinical infections could be important in transmission, silently sustaining epidemics at the population level.
“The possibility of unseen chains of transmission may silently spread through cattle, other farm animals, and humans.”
