Technology & Science

Canada geese may spread superbugs

Canada geese can carry antibiotic-resistant superbugs and may spread bacteria such as E. coli wherever they migrate: U.S. study.

Canada geese can carry antibiotic-resistant superbugs and may be spreading bacteria such as E. coli and salmonella wherever they migrate, a study suggests.

Researchers with the U.S. Centers for Disease Control spent months testing goose feces from four water areas in Georgia and North Carolina to see if the birds could pick up and deposit E. coli.

They found antibiotic-resistant strains even though the birds hadn't been treated with drugs.

Geese from a North Carolina flock that often lingered near a pig farm had particularly high levels of the superbugs – and often showed resistance to more than one antibiotic, the researchers found.

Pig farms, like other livestock-rearing operations, can use high levels of antibiotics to tamp down diseases.

"Some of these geese were landing in a lagoon that had some run-off from a pig operation," said Dr. Scott Weese, of the Ontario Veterinary College in Guelph.

"So presumably there was resistance in E. coli from some of the pigs. The geese landed in the environment and through just normal eating or grooming in that environment, they ingested the E. coli."

Although the flocks observed were non-migratory, the U.S. study – posted on the CDC's Emerging Infectious Diseases website – concludes that Canada geese could spread the pathogens.

"This species could serve to disperse bacteria between widely separated locations," warned the study, to be published in the June issue of a medical journal called Emerging Infectious Diseases.

"In addition, since these birds use farm ponds and waste lagoons and graze on pastures inhabited by cattle and other livestock, the opportunities exist for new health problems in wildlife populations to emerge."

Weese, who studies diseases that can pass between humans and animals, said that scientists have recently realized that some pathogens previously thought to be found either in animals or in humans are actually found in both.

However, he said the study shouldn't spark panic. The kinds of bugs found in the birds, E. coli and salmonella, are common – and, study or no study, most people don't want to get very close to bird droppings.