In my 18 months of taking my turn overseeing the Vancouver Island Health Authority diagnostic microbiology laboratory I have been involved in the diagnosis of 3 cases of Streptobacillus moniliformis infection.
All three were quite serious requiring several days of hospital care. All three involved pet rats. At least 2 of them were not associated with a bite but were associated with very intimate “face to face” contact with the rat. I believe there have been four more cases within the last 3 years diagnosed in our lab. Seven cases in one small city in three years associated with pet rats without bites.
Rat bite fever is a serious infection that can be fatal. All rats have S. moniliformis in their mouths. All rat owners are at risk. It is clear that close contact without a bite can transmit this infection. It seems reasonable that an attempt be made to inform rat buyers of the risk and that there is a role for public health.
Likewise physicians need to be aware of the possibility and ask febrile patients specifically about rat contact.
The most recent case is summarized here Rat Bite Fever