A lethal bird flu outbreak that has been circling the globe since 2021 peaked in Japan this week, as an agriculture ministry official said the country plans to cull more than 10 million chickens. The H5N1 strain now sweeping Japan is uniquely contagious and deadly. It poses such high risk to farmed birds, such as chickens and turkeys, that a single infection on a farm condemns the entire flock to be killed.
Around the globe, record-breaking death tolls due to the virus are becoming the norm. There has been a global death toll of more than 140 million so far is still cause for deep concern. The result has been loss of income for farmers, and soaring prices for poultry and eggs – both essential sources of affordable protein.
“In terms of the numbers of birds, farms, and countries affected, the number of birds that have been killed and the duration of the outbreak, the current epidemic is truly the largest we’ve seen in history,” says Ian Brown, chair of the joint World Organisation for Animal Health and Food and Agriculture Organisation of the UN’s Scientific Network on Animal Influenza.
Europe is in the midst of its worst-ever spate of bird flu infections with 2,500 outbreaks on farms stretching across 37 countries from October 2021-September 2022. Some 50 million birds have been culled across the continent, although the vast majority of poultry infections occurred in France. More than twelve months since the virus was first detected in late 2021, infections have remained consistently high and show little sign of slowing. In fact, they seem to be gathering pace – European data shows that in autumn 2022 the epidemic was more virulent than the same time the previous year and the number of infected farms 35 percent higher.
In the US, more states than ever before have reported instances of bird flu with an all-time high of nearly 58 million poultry affected as of January 2023.
The bird flu virus was first detected among domestic waterfowl in Southern China in 1996. The H5N1 strain currently circulating originated among wild birds whose migration patterns have accelerated its global propagation. The rate of reproduction is high; one bird is able to infect up to 100 others.
In Scotland, the coast provides a haven for migratory and sea birds and a crucial habitat for many endangered species. Great skuas currently have a total population of just 16,000, more than half of which inhabit the northwest coast. When numbers of the seabird started to die off in the summer of 2021 it was the first indicator that the H5N1 virus had arrived.
Claire Smith, policy officer for UK bird protection charity the RSPB, said deaths among great skuas, gannets, gulls, geese and even eagles continued through summer, then impacting both migratory and domestic species. By July, the Scottish government had closed off access to some seabird islands.
“There were just dead birds everywhere,” Smith says.
many species around the world have suffered similar decimation. Populations of penguins in South Africa, dalmatian pelicans in the Balkans and cranes in Israel have diminished. In the UK, birdlife that wouldn’t normally be prone to bird flu, such as barn owls and kestrels, have recently been infected. “The theory,” Smith says, “is that lots of big poultry operations have rodents, and the rodents aren’t necessarily dying of bird flu but are carrying the virus on their fur, then those barn owls and kestrels are catching them.”
Against a backdrop of environmental threats such as climate change, many may never recover their numbers. “It’s not dramatic to say there are some endangered species of wild birds that could become extinct,” Brown says. As human life has been said to be entering an age of pandemics in the wake of Covid, the same is now true for birds. “We are facing a continuous threat that these outbreaks might occur every four or five years,” says Brown.
This outbreak marks the first time bird flu has been detected in Latin America with outbreaks in Columbia, Peru, Venezuela, Chile, and Ecuador, posing a potential risk to farmed and wild birds including the unique species that inhabit the Galapagos.
Human infections are also rare and mild, although a handful of cases have been reported. “At the moment, it does not have a high ability to spread and infect people, but we can’t assume that will always be the case,” says Brown. “These viruses change and mutate over time.”
Largest global bird flu outbreak ‘in history’ shows no sign of slowing (france24.com)
