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Rat-bite Fever

What is rate-bite fever (RBF)?

Rate-bite fever is a disease caused by a germ (bacteria) carried by rats, mice, and other rodents. People can get RBF when they come into contact with an infected rodent or consume contaminated food or water. Though rare in the United States, the disease can be serious.

How does RBF spread?

People can get RBF after interacting with an infected rodent. Sometimes this involves a bite or scratch, but people handle rats who are not bitten or scratched can also get RBF. RBF can also spread through food and drink that has been contaminated by rodents. RBF cannot spread from one person to another.

Who is at risk?

Anyone who comes into contact with an infected rodent is at risk for developing RBF. People who live in rat-infested buildings, have pet rats at home, or work with rats in a laboratory or pet store may be at increased risk.

What are the symptoms?

Symptoms usually develop 3-10 days after being exposed to an infected rat, but may take as long as 3 weeks. Symptoms may include fever, vomiting, headache, muscle pain, joint pain, and rash.

People who have been infected with the bacteria will often first experience a fever, followed in 2-4 days by a rash on their hands and feet. This rash is identified by flat, reddened areas with small bumps. One or more joints may then become swollen, red, or painful.

If left untreated, the symptoms can worsen to include infections of the heart, brain, lungs, and other organs. Though rare, RBF can be fatal if left untreated.

What is the treatment?

Antibiotics are available to cure RBF.

How can I prevent RBF?

You can protect yourself from RBF by avoiding contact with rodents and the places where they have been present. This includes avoiding eating or drinking anything that may have been near rodents.

If you handle rodents, be sure to wear protective gloves, avoid touching your mouth with your hands, and wash your hands regularly.

Boston Public Health Commission
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