Backyard chickens that people keep for eggs and as pets may also offer humans other, less savory bounty—bacteria that can cause diarrhea, cramping, abdominal pain, and potentially fatal infections, a Finnish study suggests.
Researchers swabbed the bottoms of 457 birds living on 50 backyard chicken farms in Finland and also tested boot socks from their human owners. They often found the bacteria Campylobacter jejuni and Listeria monocytogenes, both of which can transmit bothersome as well as potentially more serious infections to humans.
“Most commonly, the bacteria found from these chickens can cause transient self-limiting gastrointestinal symptoms, but rarely they can also cause life-threatening infections,” lead study author Leena Pohjola of the University of Helsinki said by email.
The good news is, researchers didn’t find much evidence of Salmonella enterica, a common source of food poisoning often traced back to chicken and eggs, or of Yersinia pseudotuberculosis, another bearer of foodborne illness that can come from chickens.