Owning exotic reptiles such as snakes, chameleons, iguanas and geckos could place infants at risk of salmonella infection, according to a British study.

Researchers in the southwestern English county of Cornwall found that out of 175 cases of salmonella in children under five over a three-year period, 27% occurred in homes which had reptile pets.

If the pet is allowed to run free in the home, this poses a risk, especially if the child is at an exploratory stage of crawling or licking surfaces.

The average age of children who fell ill with “reptile-associated salmonellosis” (RAS) was just six months, said the study, led by Dan Murphy of the Royal Cornwall Hospital in Truro.

The investigation is published in a specialised British journal, Archives of Disease in Childhood.

A U.S. study in 2004 estimated that RAS was behind 21% of all of laboratory-confirmed cases of Salmonella among people aged under 21.