Scientists are sounding the alarm: the epicenter of deadly bird flu outbreaks has shifted to Europe

New strains of a dangerous disease are evolving and spreading

The epicenter of deadly bird flu outbreaks is moving from Asia to Europe and Africa, alarmed scientists warn. Researchers have found that increasing numbers of viruses in wild birds are driving the evolution and spread of new strains.

A new study has found that the epicenter of deadly bird flu outbreaks has moved from Asia to Europe and Africa, writes The Guardian.

For 25 years, avian influenza viruses have tended to emerge in Asia, but major changes in the virus and its spread among wild birds mean outbreaks are changing.

New research shows that while the 2016 and 2017 outbreaks began in China, two new H5 viruses emerged in 2020 in African poultry and in 2022 in European wild birds.

“These results highlight the shifting epicenter of HPAI [высокопатогенного птичьего гриппа] H5 beyond Asia,” the researchers write in a paper published in Nature.

The latest outbreak of the highly infectious H5N1 variant has caused the largest outbreak of bird flu in Europe before spreading around the world, The Guardian recalls. Bird flu has now reached every continent except Oceania and Antarctica, killing record numbers of domestic and wild birds and even spreading to mammals. The disease can also be transmitted to people: since 2003, the H5N1 virus has been detected in 873 people, resulting in 458 deaths, according to the World Health Organization. Most cases have been associated with handling infected poultry, and it is unknown whether it can be transmitted from person to person.

An international team of scientists led by the University of Hong Kong analyzed outbreaks between 2005 and 2022, collecting data on confirmed cases from the Food and Agriculture Organization and the World Organization for Animal Health. The researchers also examined 10,000 sets of viral DNA.

Despite the number of outbreaks, only 0.2% of cases have been sequenced, the researchers said, and they called on countries to strengthen surveillance to understand how the virus is changing. Monitoring infrastructure is particularly weak in Africa, they say. The authors suggest that the increasing persistence of avian influenza in wild birds is driving the evolution and spread of new strains.

Bird flu is highly contagious and scientists say one bird can infect up to 100 people, with the virus present in feces, mucus, blood and saliva. UK government authorities say more than 99% of poultry cases in the UK were caused by wild birds, The Guardian notes.

Mass culling was once considered an effective policy to control the spread of disease in poultry, but because avian influenza is now so widespread in wild bird populations, this measure is less effective.

The spread of avian influenza in the poultry industry is determined by human activities and how birds are traded. In wild birds, migratory routes are key indicators of where the disease will spread, with key migratory routes along the East Atlantic and Pacific Flyways, meaning it has been able to spread to new areas that have never been previously exposed to it.

Calculating how many wild birds have died is difficult because so many carcasses are never found or counted, but researchers say it is in the millions.