Cat scratch disease is a bacterial infection that normally causes swelling of the lymph nodes. It results from the scratch, lick, or bite of a cat. More than 90% of people diagnosed with this illness have had some kind of contact with cats, mostly though with kittens.

The bacteria causing this infection is called Bartonella and can be found worldwide. Mostly people get infected during fall and winter. About 20,000 cases of cat scratch disease are diagnosed in the US annually; a great part of the patients is under 21 years of age. That result is based on the fact that children are more likely to play with cats and kittens.

The bacteria are spread between cats by fleas. There is no evidence so far that fleas can transmit the disease to humans. When a cat gets infected, the bacteria live in the animal’s saliva. It does not make a cat sick, therefore cats and kittens can carry the Bartomella henselae infection for months. An estimated 50% of all cats and kittens are/have been infected at some time in their lives. Cats less than one year old and young kittens are most likely to be infected.

Signs and Symptoms
Up to three-quarters of people with cat scratch disease have a cat scratch or bite somewhere on their bodies. A blister or a small bump might develop several days after the scratch or bite. Many don’t pay attention and think this is an insect bite. Through this wound the bacteria enters the body. Some people experience more than one of these lesions, which are in general not painful.

Usually after about 2 weeks one or more lymph nodes close to the area of the inoculation lesion will swell and become tender. These swollen lymph nodes appear most often in the underarm or neck areas, although if the inoculation lesion is on the leg, then the nodes in the groin will be affected. They range in size from about 1/2 inch to 2 inches in diameter and may be surrounded by a larger area of swelling under the skin. The skin over these swollen lymph nodes may become warm and red, and occasionally the lymph nodes drain pus.

About a third of infected people will also experience other symptoms, such as fever, fatigue, loss of appetite, headache, rash, sore throat and an overall unwell feeling.

Very seldom these infections turn more serious where a person may have infections of the liver, spleen, bones, or lungs, or a lingering high fever without any other symptoms. Some people get an eye infection known as Parinaud oculoglandular syndrome. Others may develop inflammation of the brain or seizures, although this is rare. All of these complications of cat scratch disease usually resolve without any lasting illness.

Even sometimes multiple cases of the illness occur in the same family, the infection is not contagious. It’s rather likely that all of these family members had contact with the same infected animal that resulted in scratches or bites.
Having one episode of cat scratch disease usually makes people immune for the rest of their lives.

The incubation period is between 3 - 10 days (for a blister or a small bump to appear at the site of a scratch). Lymph node swelling begins about 1 - 4 weeks later. The lesion where the bacteria entered the body usually heals within 1 - 2 weeks; swollen lymph nodes normally disappear within 2 - 4 months.

You definitely do not need to get rid of your animal, even with kids in your household. A few preventive steps can go a long way toward limiting your chances of contracting the disease.

* Avoid stray and unfamiliar cats.
* Avoid rough play with any pet to limit the danger of being scratched or bitten.
* Wash your hands after handling or playing with a cat.
* If a pet scratches you or a family member, wash the injured area thoroughly with soap and water.

Keeping the house and your pet free of fleas will reduce the risk that your cat could become infected with the bacteria to begin with.