Cat Scratch Disease (Bartonella henselae Infection)

About 40% of cats carry Bartonella henselae, the bacteria that causes cat scratch disease.

Cat Scratch Disease Symptoms & Signs

Cat scratch disease, also known as catscratch disease, cat scratch fever, or subacute regional lymphadenitis, produces symptoms due to bacterial infection of the lymph nodes with bacteria known as Bartonella henselae. Most patients have a history of exposure to cats, and the disease begins with a reddish brown nodule (bump) at the site of infection. There is typically no pain or tenderness. Over the next weeks, there is enlargement of the lymph nodes that may be accompanied by tenderness.

Cat scratch disease facts*

*Cat scratch disease facts by

  • Cat scratch disease (CSD) is a bacterial disease caused by Bartonella henselae.
  • It is often caused by a bite or scratch from a cat. Kittens are more likely to pass on the bacteria. Cats who carry B. henselae do not show any signs of illness, so you cannot tell which cats could spread the disease to you.
  • Symptoms and signs of cat scratch disease include a bump or blister at the site of the scratch followed by
  • People with suppressed immune systems, such as people undergoing chemotherapy, organ transplant patients, and people with HIV/AIDS, are more likely to have complications of CSD.
  • Diagnosis of cat scratch disease is made by a history of a wound caused by a cat, physical exam showing signs of lymph node swelling, indirect fluorescence assay (IFA), and enzyme-linked immunoassay (ELISA) blood testing, and possibly lymph node biopsy.
  • Treatment for cat scratch disease includes antibiotics such as azithromycin (Zithromax), clarithromycin (Biaxin), rifampin (Rifadin), trimethoprim-sulfamethoxazole (Bactrim), and ciprofloxacin (Cipro).
  • To reduce your risk of getting CSD, avoid rough play with cats and kittens, wash cat bites and scratches thoroughly, don't allow cats to lick any open wounds you have, and contact your physician if you develop any symptoms or signs following a cat bite or scratch.

What is cat scratch disease?

Cat-scratch disease (CSD) is a bacterial infection spread by cats. The disease spreads when an infected cat licks a person's open wound, or bites or scratches a person hard enough to break the surface of the skin. About three to 14 days after the skin is broken, a mild infection can occur at the site of the scratch or bite. The infected area may appear swollen and red with round, raised lesions and can have pus. The infection can feel warm or painful. A person with CSD may also have a fever, headache, poor appetite, and exhaustion. Later, the person's lymph nodes closest to the original scratch or bite can become swollen, tender, or painful.

Wash cat bites and scratches well with soap and running water. Do not allow cats to lick your wounds. Contact your doctor if you develop any symptoms of cat-scratch disease or infection.

CSD is caused by a bacterium called Bartonella henselae. About 40% of cats carry B. henselae at some time in their lives, although most cats with this infection show NO signs of illness. Kittens younger than 1 year are more likely to have B. henselae infection and to spread the germ to people. Kittens are also more likely to scratch and bite while they play and learn how to attack prey.

Medically Reviewed by a Doctor on 9/30/2016

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