A global study has revealed that factory-farmed chickens are significantly contributing to the spread of Campylobacter, a leading bacterial cause of diarrhoea worldwide.

Researchers analysed over 2,800 bacterial genomes from chickens and wild birds across 30 countries between 1979 and 2024, finding that densely populated chicken flocks in industrial farms create ideal conditions for the bacterium to thrive.

The study highlights how these environments allow Campylobacter strains from wild birds to intermingle with commercial poultry populations, creating 'pathogen sponges' that amplify bacterial transmission.This has led to a 100-fold increase in infections compared to historical levels.Antimicrobial resistance is exacerbating the problem, making treatments increasingly difficult.The findings underscore the need for stricter biosecurity measures in factory farming to prevent further spread of this common foodborne illness.

The research suggests that when chicken populations reach critical densities, the bacteria can become self-sustaining within the farm ecosystem, posing significant public health risks.