In a new study published in PLoS Genetics, researchers extracted campylobacter DNA from patients and compared it to campylobacter DNA found in livestock, wild animals, and the environment.
The researchers developed a new evolutionary model to identify the most probable source populations. In 97% of cases, chicken, cattle, or sheep were identified as the source of infection.
In 57% of the cases, the bacteria could be traced to chicken, and in 35% to cattle. Wild animal and environmental sources were accountable for 3% of disease.
Very few cases were attributable to campylobacter found in wild animals or the environment.
The results of the study, therefore, imply that the primary transmission route is the food chain. These findings also add new impetus to measures that reduce infection in livestock and prevent food-borne transmission.
The research was led by Daniel Wilson of the University of Chicago, who stated: “The dual observations that livestock are a frequent source of human disease isolates and that wild animals and the environment are not, strongly support the notion that preparation or consumption of infected meat and poultry is the dominant transmission route.”