Pet Frogs can Infect Kids with Salmonella

It's fun to have aquatic frogs as pets, but it can put kids at a greater risk of many deadly diseases, including salmonella; a team of federal researchers warn parents.

While analyzing the reasons behind the salmonella outbreak between 2008 and 2011, Shauna Mettee Zarecki and her colleagues from the Centers for Disease Control and Prevention (CDC) found that pet frogs, specifically African dwarf frogs, were the main source of the infection that sickened and made nearly 400 Americans, mainly kids, to seek medical help during the period.

"This was the first Salmonella outbreak associated with aquatic frogs, and in this case the frogs are often marketed as good pets for kids," lead author of the study Zarecki told Reuters Health. "The majority of people didn't realize there were any risks from these amphibians or other amphibians, like turtles and snakes." 

Salmonellosis is an infection caused by bacteria called Salmonella. The bacteria, commonly found in food products like raw poultry, eggs and beef, are named after an American scientist who discovered the bug. According to an estimate from the CDC, nearly 42,000 salmonellosis cases are reported across the United States, and about 400 persons die each year due to the infection. Some of the most common strains found in the country are S. Typhimurium and S. Enteritidis.

Salmonella infection leads to diarrhea, fever, headache and abdominal cramps. The symptoms are followed by nausea, vomiting and loss of appetite. Children, especially infants, are more vulnerable to develop the infection than others.

African dwarf frogs (Hymenochirus) are small water frogs from Africa that live their whole life under water. These frogs, found in different colors including olive green and brown with black spots, live up to 20 years. African dwarf frogs require a very low cost to maintain compared to other amphibians, so they have been popular in the market as pets from the 1960s.

For the study, the researchers interviewed people who were infected with salmonella during the outbreak (2008-2011). A significant number of the infected persons revealed they were exposed to the African dwarf frog one week before developing the disease.

To re-confirm their findings, the researchers visited an African dwarf frog breeding center in Madera County in California. They found the same strain of salmonella in the center's environment, including tank water, water filters and floor drains, Reuters Health reported.

As the frogs have long life expectancy, the authors warn people to take appropriate cleaning precautions to avoid risks.

The study has been published in Pediatrics.