Link between ESBL in animals and people remains a mystery.
This finding means the role of farm animals in spreading the resistant ESBL bacterium remains a riddle. ESBL bacteria are present on 100 percent of the chicken farms, 40 percent of pig farms and half of all calf farms, but there is no direct link between the resistant bacteria in humans and in animals. One third of poultry farmers do, however, carry ESBL, sometimes with the same ESBL genes as are found in their chickens. It is not clear, then, how the transfer between animals and humans takes place. Contact with veterinary doctors might play a role, suggest Huijbers in her article in Clinical Microbiology and Infection.