Rat/Mice Diseases - Rat bite fever

Rat bite
  • Rat-bite fever is a rare disease spread by infected rodents.
  • Rats can carry the bacteria but generally do not show any signs of illness.
  • Disease can occur in humans who have been bitten by an infected rat, mice, squirrels, cats, and weasels; it can be fatal.
  • Mice may develop joint infections, sore/reddened eyes, bloody urine, diarrhea, other signs of severe disease, and even death.
  • On occasion, the disease can also be spread by ingestion of contaminated food or milk products (Haverhill fever).
  • Most cases are caused by bacteria called Streptobacillus moniliformis.
  • Another form of rat-bite fever, caused by Spirillum minus, is almost always caused by a rat bite. It cannot be caught from food or milk.
  • Person-to-person transmission does not occur. The incubation period is 3 to 10 days in most cases of S moniliformis and 7 to 21 days in cases of S minus.

    • Signs and Symptoms: Rat-bite fever symptoms can vary depending on which organism is responsible for the disease. When the disease is caused by S moniliformis, the bite, which usually heals quickly, is followed 3 to 10 days later by:
    • Fever and chills
    • Headache
    • Skin rash (mostly on the arms and leg )
    • Muscle pain
    • Arthritis (particularly in the knees)
    • Vomiting and diarrhea
    • Complications (e.g., abscesses, pneumonia, meningitis, heart inflammation)

    • Rat bite fever With infections caused by S minus, the site of the bite may appear to heal initially, but 7 to 21 days later, the following symptoms may surface:
    • Fever and chills
    • Headache
    • Ulceration at the site of the bite with red streaks
    • Swelling of the lymph nodes
    • A skin rash with reddish-brown or purple plaques
    • Muscle pain and arthritis (rare)
    • Vomiting and sore throat (Haverhill fever)
    • Complications (e.g., infection of the heart, pneumonia, meningitis, hepatitis)

    • Both forms of rat-bite fever may result in recurrent fevers, sometimes for months or years.

    • To treat rat-bite fever, the doctor will give you antibiotics (penicillin G) by injection or intravenously for 7 to 10 days.
    • Alternative drugs include ampicillin, cefuroxime, and cefotaxime.
    • With prompt treatment, most people with rat-bite fever recover completely.

    • Any animal bite should be cleaned well with soap and water. Treatment for 2 or 3 days with amoxicillin clavulanate by mouth may be helpful in preventing infection. The need for a tetanus vaccine should be reviewed.
    • Do not allow pet rodents or other pets to have contact with wild rodents, particularly rats.
    • People that handle rats or clean their cages should wear protective gloves, wash their hands after contact and avoid hand to mouth contact.