Rat-Bite Fever


Rat-Bite Fever, also known as Haverhill Fever or Epidemic Arthritic Erythema, is a bacterial infection caused by Streptobacillus moniliformis. This bacterium is carried by some rats and transmitted by secretions from the mouth, nose, eyes, feces or urine. People are infected by these secretions through bites, accidental ingestion of secretions, or exposure via broken skin barriers. The majority of infections are through bites.

Rats show no symptoms of illness. A rat with this bacterium is infected for life.

Two to ten days after being infected, a person demonstrates high fevers, rigors, headaches and painful joints. Twenty percent of patients who do not receive treatment can develop damage to the heart and brain. While rare, shock and death can occur.

People are treated with penicillin and tetracycline antibiotics. There is no known effective treatment for rats. A swab of the rat’s mouth can be submitted for a PCR test to detect this bacterium. Talk to your veterinarian about the need to test pet rats or the need to test a rat which has bitten a person. Good education and the risk of exposure should be discussed during your pet rat’s routine physical examination. Pet rats make great companions for many people, and the risk of carrying this disease is low. It is strongly recommended to test any rat who will come into contact with children, the elderly or anyone with a compromised immune system.