Rat bite fever (also called Streptobacillary fever; Streptobacillosis; Haverhill fever; Epidemic arthritic erythema; Spirillary fever; Sodoku) is an acute, rare disease caused primarily by the bacterium Streptobacillus moniliformis. In Asia, another bacterium Spirillum minus causes spirillary rat bite fever. Rat-bite fever was first described in India more than 2,300 years ago.The exact incidence across India is unknown. Rats are carriers of both bacteria but rarely show signs of illness. The majority of cases are due to the animal's bite. It can also be transmitted throughout food or water that is contaminated with rat feces or urine.
Symptoms depend on the bacteria that caused the infection. Symptoms due to S. moniliformis include chills, fever, joint pain, redness, or swelling. Symptoms due to S. minus may include chills, fever, open sore at the site of the bite, swollen lymph nodes near the bite. Symptoms usually occur 3-10 days after exposure to an infected rodent, but can be delayed as long as 3 weeks. It can be treated readily with antibiotics (penicillin and tetracyclins), but untreated S. moniliformis infections are estimated to be fatal.