The Centers for Disease Control announced yesterday that it is still investigating an outbreak of salmonella typhimurium associated with African Dwarf Frogs bred at Blue Lobster Farms in California:

This nationwide outbreak is ongoing. As of July 18, 2011, a total of 241 individuals infected with the outbreak strain of Salmonella Typhimurium have been reported from 42 states since April 1, 2009. These infections are associated with African dwarf frogs–a type of water frog–and water from their habitats (e.g., tanks or aquariums).

Epidemiologic, traceback and laboratory findings between 2009 and 2011 link this ongoing nationwide outbreak of human Salmonella Typhimurium infections to a single African dwarf frog breeding facility in Madera County, California, Blue Lobster Farms. The owner of Blue Lobster Farms voluntarily stopped shipping African dwarf frogs in late April but resumed shipping the frogs in early June. These frogs may be found in pet stores, educational stores, toy stores, fairs, carnivals, from online retailers and other venues.

Public health officials with the Madera County Department of Environmental Health are currently working with the owner of Blue Lobster Farms to conduct interventions and ongoing testing and monitoring of the frog breeding facility. At this time, the effectiveness of these interventions is unknown, and reports of ill persons infected with the outbreak strain are continuing.

Included with the update were guidelines on how to avoid infection for keepers of water frogs:

1. Wash hands thoroughly with soap and water right after handling anything, including water, that comes in contact with water frogs or from inside their habitats (e.g., tanks or aquariums). Since the water from inside their habitats can carry the same germs as the water frogs themselves, following proper hand washing practices is very important. Adults should assist young children with hand washing.

2. Kitchen sinks should not be used to empty or wash the frog’s habitat. If possible, empty and wash the habitat outside of the home, using disposable gloves. If bathtubs are used for cleaning the frog’s habitat, they should be cleaned thoroughly and disinfected with bleach. Young children should not be allowed to clean the frog’s habitat.

3. Be aware that Salmonella infections can be caused not only by water frogs, but by other amphibians and reptiles, such as turtles. More information about how to enjoy pets safely can be found on the CDC Healthy Pets Healthy People Website.

The Pet Industry Joint Advisory Council (PIJAC) has signage intended to be used as a display in pet stores where water frogs are sold that includes the CDC's guidelines to safe handling of the pets. It can be downloaded here.

A complete account of the ongoing investigation is on the CDC website.