Rat-bite fever is a rare bacterial disease spread by the bite of an infected rodent.
Streptobacillary fever; Streptobacillosis; Haverhill fever; Epidemic arthritic erythema; Spirillary fever; Sodoku
Rat-bite fever can be caused by either of two different bacteria, Streptobacillus moniliformis or Spirillum minus. Both of these are found in the mouths of rodents.
The disease is most often seen in:
Most people get rat-bite fever through contact with urine or fluids from the mouth, eye, or nose of an infected animal. This most commonly occurs through a bite or scratch. Some cases may occur simply through contact with these fluids.
A rat is usually the source of the infection. Other animals that may cause this infection include:
Symptoms depend on the bacteria that caused the infection.
Symptoms due to Streptobacillus moniliformis may include:
Symptoms due to Spirillum minus may include:
Symptoms from either organism usually resolve within 2 weeks. Untreated, the symptoms, such as fever or joint pain, can keep returning for many weeks or longer.
Exams and Tests
The health care provider will perform a physical examination and ask about your symptoms. If the provider suspects rat bite fever, tests will be done to detect the bacteria in:
Blood antibody tests and other techniques may also be used.
Rat-bite fever is treated with antibiotics for 7 to 14 days.
The outlook is excellent with early treatment. If it is not treated, the death rate can be as high as 25%.
Rat-bite fever may cause these complications:
When to Contact a Medical Professional
Call your provider if:
Avoiding contact with rats or rat-contaminated dwellings may help prevent rat-bite fever. Taking antibiotics by mouth promptly after a rat bite may also help prevent this illness.
Shandro JR, Jauregui JM. Wilderness-acquired zoonoses. In: Auerbach PS, Cushing TA, Harris NS, eds. Auerbach's Wilderness Medicine. 7th ed. Philadelphia, PA: Elsevier; 2017:chap 34.
Washburn RG. Rat-bite fever: Streptobacillus moniliformis and Spirillum minus. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, Updated Edition. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 233.
Review Date: 12/1/2018
Reviewed By: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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