..."Rat bite fever is a systemic zoonotic illness occurring following exposure to rats or, occasionally, other rodents that have oropharyngeal colonization with the causative organisms.1 In North America, cases are generally due to S. moniliformis, whereas Spirillum minus causes cases in Asia. The name "rat bite fever" is a misnomer, since a bite is not required and fever may have resolved by the time the patient seeks medical attention. In cases lacking bites, such as ours, there is typically a history of close contact with the oral flora of pet rats, through kissing and sharing food, for example. The clinical characteristics include fever, rash, myalgias, and arthralgias and arthritis, which occur 10 days after exposure. Erythematous macular or papular rashes are typical, but pustules, desquamation and purpuric lesions have been described. "...

..."Disease following the bite of a rat has been known in India for over 2,300 years, but it has been described worldwide much more recently as rat bite fever. This term describes two similar yet distinct disease syndromes caused by Streptobacillus moniliformis or Spirillum minus. Rat bite fever caused by S. moniliformis is more common in North America, while S. minus infection, also known as sodoku, is more common in Asia. Streptobacillary rat bite fever, the subject of this review, is a systemic illness classically characterized by relapsing fever, rash, migratory polyarthralgias, and a mortality rate of 13% when untreated. Often associated with the bite of a wild or laboratory rat, rat bite fever historically has affected laboratory technicians and the poor. As rats have become popular as pets, this has changed such that children now account for over 50% of the cases in the United States, followed by laboratory personnel and pet shop employees. Over 200 cases of rat bite fever have been documented in the United States, but this is likely a significant under-representation because rat bite fever is not a reportable disease. Further, rat bite fever has a nonspecific presentation with a broad differential diagnosis, and isolation and identification of its causative organism, S. moniliformis, is not straightforward. Thus, the challenges of diagnosis and broadened demographic exposure demand close attention to this disease and its causative organism by clinicians. "..."The risk of infection after a rat bite appears to be 10% (23, 35), and the mortality rate of untreated rat bite fever is approximately 13% (65, 91). "...