Flu that spread from wild birds to mink in Spain raising global alarm: Experts

OVIEDO, Spain

A recent scientific study, suggesting that a recent outbreak of avian flu on a Spanish mink farm stemmed from wild birds, is causing global alarm, according to a local media report on Tuesday.

The study, published in the medical journal Eurosurveillance, describes how a highly pathogenic avian influenza A (H5N1) killed 4.3% of all the mink on a farm in the northwestern Galicia region during a single week of the outbreak, the Spanish daily El Pais reported.

Just weeks before the mink started dying, 27 seabirds were found dead or sickened by a similar virus in the same area. The same strain has also infected wild birds and poultry across Europe.

Spanish scientists conducted a genomic analysis of the viruses. The results showed that the virus could have passed from a wild bird to the mink, and evidence supported that the virus mutated to be able to spread from mink to mink.

In response to the outbreak, which occurred in October last year, the Galician government culled 52,000 mink on the farm. The farm’s 11 workers tested negative for the virus but were put under a 10-day semi-quarantine.

Even so, the virus’s ability to jump from birds to mammals has been spreading alarm.

“It’s pretty scary. In Europe, we’ve never had an outbreak like this in mink. There had just been some cases in China,” Spanish virologist Elisa Perez told El Pais.

What worries virologists is that mink could serve as a “mixing vessel” for the virus so it could eventually spill over into humans.

“Again, in my honest opinion, we are playing with fire,” tweeted Dutch virologist Marion Koopmans, one of the 13 members chosen by the World Health Organization to investigate the origins of COVID-19, in reaction to the study.

Mink farms around the world also suffered from COVID-19 outbreaks. The danger these outbreaks posed caused Denmark — formerly the world’s largest producer of mink skins — to cull all of its mink and end the industry entirely.

In Spain, mink farms remain open, although farm workers dealing with animals have to wear facemasks.

“Two years ago, I wrote about the risks around mink and COVID. Now, we see even bigger risks for avian flu, since minks give viruses a magnificent opportunity to adapt to mammals. That’s where the next pandemic could come from,” British epidemiologist Matthew Baylis told El Pais.

Meanwhile, wild and farmed birds across Europe are suffering from the worst season of highly pathogenic avian influenza on record, with 47.7 million birds culled as of October, 2022, according to the European Food Safety Authority.

Further experimental studies are still ongoing to further explore the transmissibility of the viruses detected in Spain.