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

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 percent occurred in homes which had reptile pets.

Salmonella is a germ that, in humans, can cause gastroenteritis, colitis, blood infections and meningitis.

Reptiles, though, are unaffected by the bug, which colonises their gut and is passed on in their stools.

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.

"RAS is associated with a severe outcome -- hospitalisation and disease," it said.

"Coupled with evidence of increasing ownership of indoor reptile pets, the incidence of RAS hospitalisation is likely to increase. Health professionals such as general practitioners and paediatricians need to be aware of this risk."

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

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