Newly Emerging Flu Strain in China May Already Be Spreading Silently

A newly emerging flu virus discovered in China is raising global alarm after scientists warned it may now be capable of spreading from animals to humans—silently and swiftly, much like Covid-19.

The Influenza D virus (IDV), first detected in pigs in Oklahoma in 2011, has evolved significantly and was recently found in cattle in northeastern China.

Researchers say the virus could be crossing borders undetected and triggering hidden chains of transmission.

The study, conducted by the Changchun Veterinary Research Institute and led by Hongbo Bao, revealed that IDV has shown “alarming exposure rates” and may have acquired the ability for human-to-human transmission.

“Our findings indicate that IDV may have acquired the capacity for human-to-human transmission during its ongoing evolution,” the researchers wrote.

They confirmed that the virus can spread through both direct contact and airborne transmission among animals.

According to Express, the virus has quietly spread across multiple continents—including Europe, Asia, Africa, and the Americas—often arriving without symptoms, making it difficult to detect.

Cattle have become the primary carriers, but other animals such as goats, sheep, horses, camels, and dogs have also tested positive.

This raises serious concerns for farm workers and others in close contact with livestock.

The researchers observed that IDV’s ability to spread silently makes it particularly difficult to monitor.

“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,” they explained.

Further analysis of the D/HY11 strain found in cattle in 2023 showed that the virus can replicate in human airway cells and animal tissue.

“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 researchers concluded.

Health experts are now urging global surveillance and early intervention to monitor the virus’s evolution and prevent a potential panzootic—a pandemic-like outbreak among animals with spillover risk to humans.

With its stealthy spread and cross-species infectivity, IDV is being closely watched as a possible new threat to global health.