Many people are familiar with the risk of salmonellosis associated with turtles, but a recent multistate outbreak of human Salmonella typhimurium infections has been linked to African dwarf frogs, a common aquatic pet.
Pet frogs are popular pets, especially for small children or families who do not want a larger pet responsibility. Many people are familiar with the risk of salmonellosis associated with turtles, but a recent multistate outbreak of human Salmonella typhimurium infections has been linked to African dwarf frogs, a common aquatic pet. These small entirely aquatic frogs are frequently found in pet stores, petting zoos, and classrooms and as household pets.
In August 2009, the Centers for Disease Control and Prevention began a multistate investigation into the outbreak of infections. The results of the case-control study exposed the source of the salmonella as frogs originating from a single California breeder. Patients were likely exposed through contact with infected aquarium water in most cases, rather than from direct handling of infected frogs. This salmonella strain was isolated from several sources including aquarium water, gravel, filtration systems, and even several of the frogs themselves. The results of this investigation further suggested that much more needs to be done to educate the general public about the risk of infections associated with amphibians. When asked, 53% of case-patients knew that turtles were a source for salmonella infection, but only 31% reported knowing that infection could be the result of exposure to amphibians. This emphasizes the need to better educate people about the potential risks of pet frogs.
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Veterinarians do not routinely see these small pets, and the hazards associated with their care are not frequently discussed. Nearly 80% of the infected individuals in this outbreak were under the age of 10, and the median age was 5 years old. Younger children are more likely to reach into tank water and are less likely to wash their hands properly. Additionally, the CDC inquiry found that most frog owners were cleaning the aquariums in either kitchen or bathroom sinks. This opens the door for potential food contamination and other sources of exposure. While most individuals infected with salmonella will experience mild disease, thousands of people are hospitalized and several hundred deaths are associated with the illness every year. Young children, the elderly, and those with compromised immune systems are especially vulnerable to developing severe symptoms.
It is important for veterinarians to inquire about reptile and amphibian pet ownership and educate clients regarding appropriate care and handling of these pets. Aquariums should be cleaned, and the water should be changed regularly. This should ideally be done outside, and children should not take part in the process. If indoor tubs are used for either aquarium cleaning or frog bathing, they should be disinfected with bleach afterward. After handling frogs or coming in contact with a frog's habitat, it is important to wash hands thoroughly with soap and water. Children need adult assistance to ensure thorough hand cleaning. Young children should avoid contact with amphibians and reptiles, and households with children under the age of 5 should be discouraged from owning these pets. Additionally, owners should not let amphibians or reptiles roam throughout the house.
Veterinarians are critical to the prevention of serious illness and outbreaks in the future. Even if you do not treat exotic animals in your practice, be proactive in obtaining client information and advising clients about reptile and amphibian pet ownership.
Source: Centers for Disease Control and Prevention. Multistate outbreak of human Salmonella typhimurium infections associated with aquatic frogs—United States, 2009. MMWR Weekly 2010;58(51&52):1433-1436.