Majority of Campylobacter Cases Come from Animals

by 5m Editor
29 September 2008, at 9:41a.m.

GLOBAL - Dr Wilson of Lancaster University in the UK and colleagues have published a paper investigating the source of <em>Campylobacter jejuni</em> in human patients. From DNA analysis, they concluded that chickens, cattle or sheep were the source of 97 per cent of infections in their study.

Campylobacter jejuni is a bacterium commonly found in the guts of birds and mammals. In humans, it is responsible for causing more gastroenteritis than any other identified bacterial species. Humans may contract campylobacter from a variety of sources. Eating raw or undercooked meat or poultry, and poor food hygiene that leads to cross-contamination of uncooked food, can cause human disease. However, humans may be exposed to the faeces of infected wild animals, and campylobacter can survive in water.

Contamination of drinking water can lead to outbreaks, and previous genetic studies have suggested that livestock are not the principal source of human infection.

The authors extracted campylobacter DNA from patients and compared it to campylobacter DNA found in livestock, wild animals and the environment. They developed a new evolutionary model to identify the most probable source populations.

In 97 per cent of cases, they identified chicken, cattle or sheep as the source of infection. Very few cases were attributable to campylobacter found in wild animals or the environment.

"Our results imply that the primary transmission route is the food chain and also add new impetus to measures that reduce infection in livestock and prevent food-borne transmission," concluded the researchers.

Wilson D.J. et al., 2008. Tracing the source of campylobacteriosis. PLoS Genetics, 4(9): e1000203. doi:10.1371/journal.pgen.1000203