Real Frogs Not As Kid-Friendly as Kermit

African dwarf frogs caused salmonella outbreak among children keeping frogs as pets

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) Frogs and snakes may seem like low-maintenance pets for kids. But young children can become sick from contact with reptiles and amphibians.

In fact, over a three-year period, nearly 400 children became very sick because of their exposure to a pet frog called African dwarf frogs.

Reptiles and amphibians, as well as baby birds like chicks, can carry a bacteria called salmonella. It's similar to the salmonella found in tainted food.

However, generally only children are likely to become infected with the salmonella that a reptile or amphibian might be carrying.

When investigators from the CDC looked into a nationwide outbreak of salmonella, they discovered that it had been caused by the aquatic frogs children kept as pets.

"Keep reptiles away from small children."

The study, led by Shauna L. Mettee Zarecki, RN, MPH, of the Epidemic Intelligence Service at the Centers for Disease Control and Prevention, involved an investigation of a salmonella outbreak among children that occurred from 2008 to 2011.

The researchers began their investigation by seeking out all the children infected with the salmonella strain that was involved in the outbreak. They located 376 children across 44 states.

None of the infected children died, but nearly a third of them (56 patients) were hospitalized. Half the children were younger than age 5 and 69 percent were under 10.

Next, the researchers located 376 other children who had been infected with other strains of salmonella not related to this outbreak. Each of these children was matched with a child in the first group in terms of age and state.

Then the researchers investigated the homes of children in both groups and conducted extensive interviewing with children from both groups.

The researchers conducted interviews with 114 of the patients who had the outbreak strain and discovered that 69 of them, or 61 percent of them, had been exposed to frogs.

Not all of the families knew what kind of frog they had been exposed to, but among the 56 children who did, 79 percent of them reported that it was an African dwarf frog. These are aquatic frogs often kept as pets.

Then the researchers compared the children exposed to frogs in the outbreak group to the children exposed to frogs in the non-outbreak group.

They found that 67 percent of the children who became infected with the outbreak strain of salmonella had been in contact with frogs. Meanwhile, only 3 percent of the children with non-outbreak strains had been exposed to frogs.

An analysis of these differences revealed that the young children who were exposed to frogs were 12 times more likely to have become infected with the strain of salmonella that was involved in the outbreak.

The researchers then took samples from the African dwarf frog aquariums in eight patients' homes, in a daycare center and in two pet stores selling the frogs. The researchers found that the salmonella carried by these frogs looked exactly the same as the one involved in the outbreaks.

The researchers then followed the trail back to where the frogs had come from. The researchers found that all the frogs originated from an African dwarf frog breeding facility, where tests revealed the same salmonella strain that had caused the outbreak.

It was therefore clear that keeping African dwarf frogs as pets among children had led to the salmonella outbreak.

"This outbreak highlights the ongoing public health problem of salmonellosis among children from exposure to certain high-risk animals, such as amphibians (e.g., frogs), reptiles (e.g., turtles) and baby poultry," the researchers wrote.

The study was published March 11 in the journal Pediatrics. The research did not receive external funding. The authors reported no conflicts of interest. The photo of the African dwarf frog is by Lotzman Katzman.

Reviewed by: 
Review Date: 
March 8, 2013
Last Updated:
August 15, 2013