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Cat-Scratch Disease

• Cat-scratch disease is a bacterial disease that results from a scratch or bite by a cat. Persons with cat-scratch disease can have a range of illnesses from mild to severe.
• Cat-scratch disease usually causes swollen lymph glands near the site of the scratch or bite.
• Most people get better on their own in about 3 weeks.
• To prevent cat-scratch disease, avoid provoking cats and kittens. Thorough cleaning of cat scratches and bites might also help.

What is cat-scratch disease?

Cat-scratch disease is an infectious disease that results from a scratch or bite by a cat. Persons with cat-scratch disease can have a range of illnesses from mild to severe.

What is the infectious agent that causes cat-scratch disease?

Cat-scratch disease is caused by Bartonella henselae, a bacterium.

Where is cat-scratch disease found?

The bacterium that causes cat-scratch disease is found in all parts of the world. The bacterium is carried by cats and kittens. Infected animals do not become sick.

How is cat-scratch disease spread?

The disease is spread by a scratch or bite from a cat, most often a kitten. The infection spreads from the site of the scratch or bite to the lymph glands. Cats that spread the infection do not look sick. The infection is not spread from person to person.

What are the signs and symptoms of cat-scratch disease?

A blister or sore, with or without pus or fluid, often shows up on the skin at the place where the bacteria entered the body. Within 2 weeks, the lymph glands nearby usually become swollen and tender. In most children and adolescents, swollen glands are the main symptom. Adults often have other symptoms such as low fever, tiredness, headache, and loss of appetite. About 5% of persons with cat-scratch disease develop irreversible retinitis (inflammation of the retina of the eye) or encephalitis (inflammation of the brain). Persons with weakened immune systems can become more seriously ill.

How soon after exposure do symptoms appear?

It usually takes 3 to 10 days for a sore to appear at the site of a cat scratch or bite. The lymph glands nearby usually start to swell about 2 weeks after the scratch or bite.

How is cat-scratch disease diagnosed?

Diagnosis is based on symptoms and a history of a scratch by a cat. A blood test can confirm the diagnosis.

Who is at risk for cat-scratch disease?

Anyone can get cat-scratch disease. Most cases are in children and adolescents. Persons who own or handle cats are at increased risk.

What complications can result from cat-scratch disease?

In rare cases (1%-5%), cat-scratch disease can cause complications such as an irreversible inflammation of the eye or seizures (convulsions).

What is the treatment for cat-scratch disease?

Most people recover on their own within 3 weeks. Tenderness and swelling can be relieved by putting warm soaks or a heating pad on the sore area. Persons with severe pain or symptoms are sometimes treated with antibiotics. A doctor may need to open and drain painful, red lymph glands that contain pus.

A veterinarian should be contacted about the cat or kitten that caused the infection. Steps to minimize scratching and biting should be taken. Cats with cat-scratch disease do not need to be destroyed.

How common is cat-scratch disease?

In the United States, about 24,000 persons get cat-scratch disease each year. Most are children and young adults.

Is cat-scratch disease an emerging infectious disease?

Yes. The disease was recognized recently, and the bacterium that causes it was recently isolated.

Cats are one of the most frequently kept pets in the United States, numbering more than 60 million.

How can cat-scratch disease be prevented?

• Teach children to respect animals and not to provoke them.
• Do not pick up strange cats.
• Thorough cleaning of cat scratches and bites might be helpful.

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