Notes from the field: update on human Salmonella Typhimurium infections associated with aquatic frogs--United States, 2009-2011.

CDC is collaborating with state and local public health departments in an ongoing investigation of human Salmonella Typhimurium infections associated with African dwarf frogs (ADFs). ADFs are aquatic frogs of the genus Hymenochirus commonly kept in home aquariums as pets. From April 1, 2009 to May 10, 2011, a total of 224 human infections with a unique strain of S. Typhimurium were reported from 42 states. The isolates are indistinguishable by pulsed-field gel electrophoresis and multiple-locus variable-number tandem repeat analysis. This outbreak likely includes considerably more than the 224 laboratory-confirmed cases reported to CDC; only an estimated 3% of Salmonella infections are laboratory confirmed and reported to surveillance systems. Surveillance for additional cases continues through PulseNet, the national molecular subtyping network for foodborne disease surveillance.