Rat-bite fever (RBF) is an infectious disease that can be caused by two different Gram negative bacteria. Streptobacillary RBF is caused by Streptobacillus moniliformis in North America while spirillary RBF or sodoku is caused by Spirillum minus and occurs mostly in Asia. People usually get the disease from infected rodents or consumption of contaminated food or water. Disease has been reported in mice, birds, guinea pigs, and nonhuman primates. The majority of cases are due to the animal's bite. Symptoms of the streptobacillary form include recurrent fever, rash, and arthralgias. The spirillary form causes relapsing fever, rash, and regional lymphadenitis.
RBF is diagnosed by isolating S. moniliformis from blood, synovial fluid, or other body fluids. The disease is most often seen in Asia, Europe, North America. The exact incidence is unknown. Higher risk groups include laboratory workers, the owners of pet rats, pet shop personnel and veterinarians, as well as people who are exposed to wild rats. The disease can be treated easily with antibiotics (penicillin or tetracyclines for 7-14 days). Proper hygiene practices help in preventing the spread of the infection.