The bird flu virus currently affecting poultry farms across the United Kingdom may be the most infectious strain seen to date, raising significant concern among experts and farmers alike. Professor Ian Brown, a leading avian virologist formerly serving as director of science at the Animal and Plant Health Agency (APHA) and now affiliated with the Pirbright Institute, has issued a stark warning. He cautions that farmers need to “prepare for the worst” as the outbreak shows signs of escalating beyond previous episodes in scale and severity.
In response to the growing threat, the UK government implemented a mandatory housing order in England starting Thursday, requiring all outdoor poultry to be kept indoors. This measure aims to reduce contact between farmed birds and wild birds, which are the primary vectors of the highly pathogenic avian influenza (HPAI) H5N1 strain currently circulating. The government hopes that this will help bring infection rates down from the dangerously high levels observed in recent weeks.
This bird flu season began in October and has already seen 26 confirmed outbreaks on farms across the UK, with 22 occurring in England alone. Each outbreak necessitates the culling of entire flocks to prevent further spread, a devastating prospect for farmers both economically and emotionally. The scale of the crisis is underscored by Professor Brown’s comparison to the previous epidemic between 2021 and 2023, which saw over 350 outbreaks nationwide—a level he describes as “off the scale.” While it is difficult to predict the final impact of the current season, early indicators suggest it could be similarly severe or worse.
Professor Brown characterizes the current virus strain as “as super-infectious as any high pathogenicity avian influenza we’ve ever seen.” Given this, he stresses the urgent need for the poultry industry to “batten the hatches down,” enhance biosecurity protocols, and intensify efforts to contain the virus. The message to farmers is clear: vigilance and strict adherence to safety measures are critical to preventing widespread devastation.
One farmer deeply affected by the new regulations is Sarah Godwin, who runs a mixed family farm near North Wraxall in Wiltshire alongside her husband and brother-in-law. Their farm includes 32,000 laying hens that normally enjoy free-range access to outdoor space for much of the day. However, under the new government directive, the hens must now remain indoors at all times. While Mrs. Godwin acknowledges how distressing it is to confine the birds, she accepts it as a “necessary evil” given the high risk and potentially disastrous consequences of an outbreak.
Despite implementing stringent biosecurity measures and housing the birds indoors, Mrs. Godwin remains anxious about the possibility of infection. She explains that it only takes a minuscule amount of contaminated material—such as dirt carried in on boots or from wild bird droppings—to infect an entire flock. “It’s literally grammes that can infect the whole flock,” she says, emphasizing the fragility of the situation. Should an outbreak occur, it would mean culling all 32,000 birds, a devastating blow for any producer.
Public health authorities continue to reassure the general population that the risk to human health remains very low. The UK Health Security Agency (UKHSA) states that the chance of transmission from birds to humans is minimal. Similarly, the Food Standards Agency (FSA) confirms that bird flu poses a very low food safety risk, and that properly cooked poultry and eggs are safe for consumption.
Nonetheless, Professor Brown cautions that the virus requires ongoing monitoring due to its potential to mutate. Influenza viruses, including avian strains, are prone to genetic changes as they replicate. While these viruses currently remain adapted primarily to birds and are not well-suited to infect humans, mutations could arise that increase their infectiousness or transmissibility in people. “We have to continually monitor the virus, because it’s an influenza virus and influenza viruses change,” he explains. “Even when they’re happy in a species such as birds, they still undergo changes. They make mistakes and errors when they replicate. So that could always spew out a variant that might be more infectious for humans.”
In light of the current threat, the UK’s chief veterinary officer, Christine Middlemiss, has urged all bird keepers to fully comply with the housing order and maintain “robust biosecurity measures.” She emphasizes the importance of vigilance and prompt reporting of any suspicious signs of disease to the Animal and Plant Health Agency to enable quick