CDC is collaborating with public health officials in many states to investigate a multistate outbreak of human Salmonella serotype Typhimurium infections due to contact with water frogs including African Dwarf Frogs. Water frogs commonly live in aquariums or fish tanks. Amphibians such as frogs and reptiles such as turtles, are recognized as a source of human Salmonella infections. In the course of routine assessment, a number of cases with the same strain have been identified over many months.

As of 12pm EST on December 7, 2009, 48 individuals infected with the outbreak strain of Salmonella Typhimurium have been reported from 25 states. The number of ill persons identified in each state is as follows: Arizona (1), California (2), Colorado (2), Florida (1), Georgia (1), Idaho (1), Illinois (5), Kentucky (1), Louisiana (1), Massachusetts (2), Maryland (2), Michigan (3), Minnesota (1), Missouri (2), Mississippi (1), New Jersey (2), New Mexico (1), New York (1), Ohio (2), Pennsylvania (3), Tennessee (2), Texas (3), Utah (6), Virginia (1), and Washington (1).

Among the persons with reported dates available, illnesses began between June 24, 2009 and November 14, 2009. Infected individuals range in age from <1 year old to 54 years old. Seventy-seven percent (77%) of patients are younger than 10 years old and the median age is 4 years. Fifty-five percent (55%) of patients are female. No deaths have been reported.

Investigation of the Outbreak

In an epidemiologic study, ill persons answered questions about contact with animals and foods consumed during the days before becoming ill and investigators compared their responses to those of persons of similar age and gender previously reported to State Health Departments with other illnesses. Preliminary analysis of this study suggests contact with frogs, including water frogs such as African Dwarf Frogs, is a likely source of the infections. In addition, environmental samples taken from aquariums containing aquatic frogs in three homes of ill persons have yielded isolates of Salmonella Typhimurium matching the outbreak strain.

Advice to Consumers

Always wash hands thoroughly with soap and water after touching any amphibian (e.g., frog) or reptile (e.g, turtle), their housing, or anything (for example, food) that comes in contact with them or their housing. Adults should assist young children with hand washing.

Watch for symptoms of Salmonella infection, such as diarrhea, fever, and abdominal cramps. Call your health care provider if you or a family member have any of these symptoms.

Persons who should avoid contact with amphibians and reptiles and their habitats (e.g., aquarium, fish tank, or terrarium)

Persons at increased risk for serious infection from salmonellosis are children < 5 years old, elderly persons, and persons with weakened immune systems.

These persons should avoid contact with amphibians (e.g., frogs) and reptiles (e.g., turtles) and anything that comes in contact with them (e.g., aquarium, habitat, and water).

Keep amphibians and reptiles out of homes with children < 5 years old or people with weakened immune systems.

Placement and maintenance of habitats

Amphibians (e.g., frogs) and reptiles (e.g., turtles) should not be kept in child-care centers.
Habitats containing amphibians or reptiles should not be kept in a child’s bedroom, especially children aged < 5 years.

Do not allow amphibians or reptiles to roam freely through the house, especially in food preparation areas.

Keep amphibians and reptiles out of kitchens and other areas where food and drink is prepared or served to prevent contamination.

Habitats and their contents should be carefully cleaned outside of the home. Use disposable gloves when cleaning and do not dispose of water in sinks used for food preparation or for obtaining drinking water.

Do not bathe animals or their habitats in your kitchen sink. If bathtubs are used for these purposes, they should be thoroughly cleaned afterward. Use bleach to disinfect a tub or other place where reptile or amphibian habitats are cleaned.

Children aged <5 years should not clean habitats.

Always wash hands thoroughly with soap and water after cleaning habitats.