The US CDC is investigating a large, long-lasting and widely dispersed outbreak of salmonellosis that has been linked to contact with pet frogs, such as African dwarf frogs (see image). Between April 1, 2009 and April 5, 2011, 217 infections were identified in people in 41 states. A strain of Salmonella Typhimurium has been implicated.
Of the 217 infected people, 34% were hospitalized, which is quite a large proportion, but is probably due (at least in part) to the fact that stool samples aren’t often cultured from people with milder disease (who don’t go to the hospital). If you have severe diarrhea and are in hospital, you’re more likely to be tested. As with most outbreaks, the 217 diagnosed cases presumably represent only the tip of the iceberg.
Of the people who got sick, 64% reported contact with frogs in the week before their illness began. Of these, 84% had contact with African dwarf frogs. This type of widespread outbreak with a single strain and a fairly clear link to a specific type of animal raises questions about whether there’s a major breeder or supplier that is the source of the problem. Not surprisingly, the investigation identified a single water frog breeder in California as the source of frogs associated with this outbreak. Salmonella was identified from environmental samples at the breeder’s facility. Testing is still apparently underway to confirm whether it’s the outbreak strain, but it’s pretty likely.
As with any other reptiles or amphibians, there are standard recommendations to avoid infections from aquatic (water) frogs:
- They should not be in households with high-risk people: children less than five years of age, the elderly, pregnant women and immunocompromised individuals.
- Care should be taken to prevent contamination of the house from aquarium/terrarium water.
- To avoid contamination, aquarium water should not be dumped down kitchen or bathroom sinks.
- Hands should be washed thoroughly after contact with aquarium water or the frogs themselves.
Photo: An African dwarf frog (Hymenochirus boettgeri) (photo credit: James Gathany).