Cat Scratch Disease – Definition, Risk factors, and Prevention.

Definition

Cat scratch disease is an infection you can get after a cat scratches, bites, or licks you. It is caused by bacteria in cat saliva. Cats likely get the bacteria from fleas. Cat-scratch disease is also called cat-scratch fever. It is not a severe illness in healthy people. But it can be a problem for young children or people with weak immune systems. These include people with cancer, diabetes, or acquired immunodeficiency syndrome (AIDS).

Original wound of cat scratch disease

History

Symptoms similar to CSD were first described by Henri Parinaud in 1889, and the clinical syndrome was first described in 1950 by Robert Debré. In 1983, the Warthin-Starry silver stain was used to discover a Gram-negative bacillus which was named Afipia felis in 1991 after it was successfully cultured and isolated. The causative organism of CSD was originally believed to be Afipia felis, but this was disproved by immunological studies in the 1990s demonstrating that cat-scratch fever patients developed antibodies to two other organisms, B. henselae (originally known as Rochalimea henselae before the genera Bartonella and Rochalimea were combined) and B. clarridgeiae, which is a rod-shaped Gram-negative bacterium.

Epidemiology of Cat Scratch Disease

• CSD disease has been reported worldwide; however, the international incidence is unknown. Seroprevalence rates vary greatly throughout the world, ranging from 0.6-37% and reflecting cat populations in each country. The disease is more prevalent in areas with warm humid climates.
• In temperate climates, catscratch disease predominantly occurs in autumn and winter; in the tropics, seasonal changes in frequency of the disease are not observed. Sanguinetti-Morelli et al (2011) found that in France, most cases of CSD occurred from September to April, with a peak in April.
• At least 2 genotypes of B henselae have been isolated from cats in Europe. B henselae is endemic in Europe, Africa, Australia, and Japan. In Germany, B henselae was the causative agent of head and neck lymphadenopathy in 61 (13.4%) of 454 patients and the most common cause of lymphadenopathy in adults and children.

Risk factors

• A number of factors increase the risk of developing cat scratch disease. Not all people with risk factors will get cat scratch disease. Risk factors for cat scratch disease include:
• Any type of play with a cat, especially a kitten, that may provoke biting or scratching
• Weakened immune status, such as occurs in people who have AIDS (acquired immunodeficiency syndrome), are undergoing cancer treatment, or have had an organ transplant

Causes

Cat-scratch disease is caused by the bacteria Bartonella henselae. The disease is spread through contact with an infected cat (a bite or scratch) or exposure to cat fleas. It also can be spread through contact with cat saliva on broken skin or mucosal surfaces like those in the nose, mouth, and eyes.

Symptoms of Cat Scratch Disease

The signs and symptoms that follow may include

• Fever,
• Chills,
• Nausea,
• Vomiting,
• Fatigue,
• Loss of appetite,
• Headache,
• Joint pains,
• Sore throat, and
• Swelling and tenderness of the lymph nodes (swollen glands).

As the disease progresses, more nodules may develop under the skin at the point of injury.

Lymph nodes (Swollen glands)

What are the Complications from Cat Scratch Fever?

There are a number of possible complications from cat scratch fever.

Encephalopathy

Encephalopathy is a brain disease that can occur when the bacteria responsible for cat scratch fever spread to the brain. In some cases, encephalopathy results in permanent brain damage or death.

Neuroretinitis

Neuroretinitis is an inflammation of the optic nerve and retina in the eye that causes blurred vision. The inflammation can occur when the bacteria responsible for cat scratch fever travels to the eye, causing impaired vision. Vision usually returns to normal after the infection is gone.

Osteomyelitis

Osteomyelitis is a bacterial infection in the bones, which can result in bone damage. In some cases, the bone damage is so severe that amputation is necessary.

Parinaud Oculoglandular Syndrome

Parinaud oculoglandular syndrome is an eye infection that produces symptoms similar to pink eye. Cat scratch fever is one of the most common causes of the syndrome. Parinaud oculoglandular syndrome can be due to Bartonella henselae entering the eye directly, or by the bacteria traveling through the bloodstream to the eye. The syndrome usually responds well to antibiotic treatment. In rare cases, surgery is necessary to remove infected tissues from the eye.

Diagnosis and test

• If your doctor believes you may have cat scratch fever, they will perform a physical examination to see if you have an enlarged spleen (an organ above your stomach).
• Cat scratch fever is difficult to diagnose from the symptoms alone. Doctors can make an accurate diagnosis by performing an indirect fluorescent antibody (IFA) blood test to see if the Bartonella henselae bacteria are present in your body.
• In this test, antibodies that are labeled with dye will attach to existing antibodies of Bartonella (sometimes called anti-antibodies) and “light up” during the test.

Treatment and medications

In most people, cat-scratch disease clears up without treatment. You can take an over-the-counter pain reliever to help relieve pain and discomfort. Ibuprofen (Motrin, Advil) or naproxen (Aleve) can help. Applying heat compresses to the affected area may also help. If a lymph node is very large or painful, your doctor may drain it to help relieve the pain.

Moist Compress

It can be given to a child or the patient to be able to ease the soreness of the nodes.

Lymph node Aspiration

It may only be required when there is a presence of suppuration. The use of aspiration may be considered to be as a therapeutic as well as a diagnostic approach. When a person reports of recurrent pain and pus reaccumulation, there may be a need for repetition of aspiration procedure.

Surgical Excision

It is done especially if the person has already a presence of an enlarge nodule which may be indicated when there is a continuous repetition of aspiration and still fail to relieve the pain that the person reports to have. The physician may suggest excising a persistent granuloma.

Pharmacological Medication

Antibiotics are the medications often given to eradicate the bacteria that cause this disease condition. Antibiotics may vary depending on the individual’s reaction to such. The following are the suggested antibiotics used for persons who have cat scratch disease:

• Azithromycin
• Rifampin
• Ciprofloxacin
• Doxycycline
• Gentamicin
• Erythromycin
• Clarithromycin
• Sulfamethoxazole
• Trimethoprim

Aside from antibiotics, one can take pain relievers such as ibuprofen and acetaminophen. One should take note that, aspirin should be avoided especially with children.

Prevention of Cat Scratch Disease

• Exclusion from childcare, preschool, school or work is not necessary
• Avoid cat bites and scratches – do not ‘play rough’ with cats or kittens
• Wash cat bites and scratches immediately with soap and running water
• Do not allow cats to lick any open wounds
• Cover any open wounds with a dressing
• Control fleas in your pets even though cat-scratch disease doesn’t seem to be passed to humans by flea bites, there is evidence that it is spread between cats by fleas.