An infectious disease transmitted in the secretions of the mouth, nose or urine of an infected rodent, most commonly via a rat bite.
Alternative Names
Streptobacillary fever; Streptobacillosis; Haverhill fever;Epidemic arthritic erythema; Spirillary fever; Sodoku
Causes, incidence, and risk factors
Rat-bite fever is an infection which is caused by two different organisms, Streptobacillus moniliformis and Spirillum minus. It is rare in North and South America. The form caused by Spirillum minus , termed Sodoku, is common in Asia, predominantly in Japan. Most people acquire rat bite fever through contact with urine, oral (mouth) or conjunctival (eye or nose) secretions from an infected animal (usually rats, but rarely other animals such as squirrels, weasels and gerbils). This most commonly occurs via a bite, yet some cases may occur without an actual bite. In rat bite fever due to Streptobacillus moniliformis , fever, chills, headache and muscle pain usually occur within 10 days of exposure, followed within 3 days by a diffuse rash primarily in the extremities. One or several large joints may become swollen, red and painful. If untreated, several complications including infection of the heart valves may occur. In the form of rat-bite fever caused by Spirillum minus (Sodoku), a particular skin rash characterized by red or purple plaques is frequently seen, and the previously healed wound at the site of the bite may reactivate and open. Joint involvement is rare.
Signs and tests
Diagnosis is made by detection of the organism in skin, blood, joint fluid or lymph nodes in culture. Blood antibody tests may also be used.
Treatment
Rat-bite fever is treated with antibiotic therapy -- penicillin or tetracyclines for 7-10 days.
Expectations (prognosis)
The prognosis is excellent with early treatment.
Calling your health care provider
Call your health care provider if you or your child have had recent contact with a rat or other rodents, particularly if the person has been bitten or has symptoms of Rat-bite fever.
Prevention
Avoiding contact with rats or rat-contaminated dwellings may help prevent rat-bite fever. A course of oral antibiotics following a rat-bite may also help prevent this illness.