Rat-bite Fever (RBF)

What is Rat-bite fever?

Rat-bite fever (RBF) is an infectious disease that is caused by two types of bacteria, one called Streptobacillus moniliformis which is the cause of disease in North America, and one called Spirillum minus which is the cause for this disease in Asia. People usually get the disease from contact with infected rodents or consumption of contaminated food or water. When the source is contaminated food or water, the disease is often known as Haverhill fever. If not treated, RBF can be a serious or even fatal disease.

Who gets Rat-bite fever?

While anyone can become ill with RBF, those who live in buildings with rat infestations, those who handle rats as part of their job (such as those who work in laboratories or pet stores), or those who have rats as pets, may be at increased risk.

How is Rat-bite fever spread?

RBF is not spread from one person to another. The most common ways the RBF bacteria is spread are:

  • Bites or scratches from infected rodents (such as rats, mice, and gerbils).
  • Handling rodents with the disease (even without a bite or scratch).
  • Consuming food or drink contaminated with the bacteria from rodent droppings or urine.

What are the symptoms of Rat-bite fever?

People with RBF will often develop a fever and a rash as well as joint pain, muscle aches and a headache.

How soon after exposure do symptoms appear?

Symptoms usually occur 3-10 days after exposure to an infected rodent, but can be delayed as long as three weeks. By this time, any associated bite or scratch wound has usually healed.

How is Rat-bite fever diagnosed?

RBF should be suspected in people with rash, fever, and arthritis and a known or suspected history of rodent exposure. The bacteria that causes RBF can be hard to grow in culture, but can sometimes be identified in blood or other body fluids.

What is the treatment for Rat-bite fever?

If you have symptoms of RBF after exposure to rats or other rodents, immediately contact your health care provider. Be sure to tell your provider of your exposure to rodents.

If you have RBF, your doctor can give you antibiotics that are highly effective at curing the disease. Penicillin is the antibiotic most often used. If you are allergic to penicillin, your doctor can give you other antibiotics.

How can Rat-bite fever be prevented?

You can protect yourself from RBF by:

  • Avoiding contact with rodents or places where rodents may be present.
  • Avoiding consumption of food, milk or water that may have come in contact with rodents.

If you handle rats or clean their cages:

  • Wear protective gloves.
  • Avoid touching your mouth and face after handling rodents.
  • Practice regular hand washing.

How can I learn more about Rat-bite fever?

November 2018

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