By GB News (World News) | Created at 2026-07-28 12:35:59 | Updated at 2026-07-28 13:57:23
1 hour ago
A landmark study has revealed that the global expansion of intensive chicken farming is driving the rapid spread of campylobacter, the most prevalent bacterial source of diarrhoeal illness worldwide.
The research, newly published in the Proceedings of the National Academy of Sciences, documents a staggering 100-fold rise in the transfer of bacterial strains between domesticated chickens and wild bird populations since 1900.
Scientists at the University of Oxford led the work, which warns that modern poultry production has effectively turned chickens into a breeding ground for dangerous new pathogen variants.
Growing antimicrobial resistance among circulating strains is compounding the threat, potentially undermining doctors' ability to treat severe cases of infection in humans.
Chicken populations have increasingly picked up strains from different wild birds
GETTY
"As the chicken population has exploded, they've increasingly picked up strains from different wild birds and become a cauldron of bacterial evolution," said Prof Sam Sheppard, the paper's senior author.
"Lots of strains come together and hybridise. We do not want that, because that's where new Frankenstein monster bugs emerge."
Campylobacter is responsible for more than three times the number of gastroenteritis cases in Britain each year than all other monitored foodborne bacteria put together.
Between 60 and 80 per cent of infections are estimated to originate from raw chicken.
"Cooking kills pathogens, but just a tiny splash and it's on your lettuce leaves or your hands or your knife," Prof Sheppard cautioned.
Whilst most patients recover without medical intervention, antibiotics are sometimes necessary. Infection also elevates the likelihood of developing irritable bowel syndrome.
Of particular concern is the mounting problem of antimicrobial resistance, whereby bacteria develop the capacity to withstand drugs intended to destroy them.
Certain antibiotics once relied upon to combat Campylobacter have already lost their effectiveness, leaving clinicians with a diminishing arsenal of treatments.
The study drew upon close to 2,800 bacterial genomes gathered from chickens and wild birds across 30 nations — among them Britain, the United States and China — over a period spanning 1979 to 2024.
By reconstructing evolutionary lineages, the researchers traced how campylobacter strains were once closely associated with individual wild bird species, with minimal cross-infection prior to the chicken's domestication some 5,000 years ago.
That picture shifted dramatically as poultry numbers surged.
Since the 1960s, the global chicken population has grown sevenfold to roughly 27 billion, now representing approximately 70 per cent of all bird biomass on the planet.
"The scale is what's bad," Prof Sheppard said. "By adjusting the world's ecosystems in this dramatic way, it leads to the evolution of pathogens within those birds. That's a massive risk to us. We can't continue to produce chickens at this huge capacity."
The researchers further identified genetic alterations in Campylobacter linked to its adaptation within poultry environments.
Among these were genes conferring antimicrobial resistance, enabling the bacteria to flourish in industrial production systems where antibiotics are routinely administered — both to accelerate growth and to suppress disease in overcrowded sheds.
Intensive breeding practices have produced birds that reach full size and are sent to slaughter at just five weeks of age, a pace of production that critics argue is unsustainable.
Some antibiotics once relied upon to combat Campylobacter have already lost their effectiveness
GETTY
Maya Pardo, legal coordinator at Communities Against Factory Farming, condemned the findings as further evidence of a system in crisis.
"Intensive chicken farming has spread out of control in the UK, and the 100-fold increase in the movement of Campylobacter is the latest in a long list of devastating consequences," she said.
"While communities are desperately calling for no more factory farms, the government is absurdly looking to relax planning rules to build yet more of these disease-ridden industrial facilities."
