Cat Scratch Disease, Bartonellosis

Cat scratch disease affects over 20,000 people each year. People, especially children and young adults present develop enlarged, tender lymph nodes of unknown cause. The majority of cases are believed to be caused by a rickettsial organisms called Rochalimaea henselea. A smaller number of cases may be caused by Afipia felis bacteria. Both have been found in infected tissue of people with cat scratch disease. Owners of kittens younger than 12 months were 15 times more likely to develop CSD than owners of adult cats.

The cat, which is a carrier of the infection, is able to transmit the disease to humans during a two or three week period. In 90% of the cases people have been bitten, licked or scratched by a cat or a kitten. This means that the infective organism is carried in the cat's mouth and may be transferred to its claws during self-grooming. Three to 10 days after exposure, a raised red sore develops at the site of transmittal. This occurs in about 50% of the cases. There may be a red streak up the arm or leg. In all cases there is tender enlargement of lymph nodes in the armpit, neck or groin. This condition may persist for two to five months.

Signs and Symptoms

About 5% of those infected develop low grade fever, fatigue, headache and loss of appetite. In rare cases the spleen, brain, joints, eyes, lungs and brain may be involved. In people with other serious health conditions this infection may be life-threatening. Sometimes, patients appear to be quite well generally, with only mild, non-specific symptoms such as headache, anorexia, myalgia or abdominal pain. The illness proceeds asymptomatically or with topical symptoms of infection such as a lump, spot or blister. Within 14 days a high fever and topical lymph nodes become sore and start forming pus. In half of patients, these symptoms may resemble malignancy, and in single cases there are symptoms associated with the musculoskeletal system, such as: osteitis, arthitis and myositis.

Recently, there have been multiple cases of infection by microorganisms called Bartonella henselae and Bartonella clarridgeiae. Early symptoms may include fever, weight loss, excessive sweating, chills, painfully enlarged lymph nodes, sometimes with ascesses. These may be followed by inflammation of the eye and subsequent retinal detachment that may result in neuroretinitis with partial or total loss of vision. All people infected by Bartonella had a history of cat scratch or bite. There have been reports of encephalopathy in children who have been diagnosed with status epilepticus, as well as osteomyelitis.

Cases lasting up to 2 years have been reported, and more serious complications may occur. Many manifestations of the disease have been reported, such as serous otitis media combined with vertigo due to labyrinthitis.2 A case of a patient who had CSD and six months later developed infectious endocarditis of the mitral valve caused by B. henselae has been reported.3


Since the causative bacteria cannot be easily cultured from human lymph node samples, the diagnosis relies on multiple tests, including testing for Bartonella antibodies and detection of Bartonella DNA in patients' samples. Consult your doctor and follow her or his recommendations for diagnostic tests and treatment. In case of infections caused by Bartonella (bartonellosis), you may require up to 6 months of treatment to improve your visual acuity. In case of bartonellosis, the long-term progression is usually good, but urgent medical treatment is essential.

Cat scratch disease
Cat scratch disease

Many infected cats do not show signs of illness, but some develop fever, lethargy, swollen lymph glands, inflamed eyes and gums, and neurological disease, requiring treatment by a veterinarian. Cat owners should use a good flea control, keep cats' claws trimmed short, and discourage rough play to prevent scratches and bites. If you are bitten or scratched, wash the area immediately with soap and water. Do not let cats, or any animal, lick open wounds on your body. If one family member becomes infected, quarantine the cat for 2 to 3 weeks to prevent it from infecting others. A a precaution, sick children and immunodeficient individuals should avoid contact with cats under one year of age.


  1. Status Epilepticus Due to Cat Scratch Disease: Recognition, Diagnosis, and Thoughts on Pathogenesis. Schuster AL1, Honeycutt TC, Hamrick HJ. Pediatr Emerg Care. 2016 Nov;32(11):789-791.
  2. Serous labyrinthitis as a manifestation of cat scratch disease: a case report. Ilias KantasEmail author, Michael Katotomichelakis, Marinos Vafiadis, Zografia V Kaloutsa and Chariton E Papadakis Journal of Medical Case Reports20093:7405
  3. From cat scratch disease to endocarditis, the possible natural history of Bartonella henselaeinfection. Frédérique Gouriet, Hubert Lepidi, Gilbert Habib, Frédéric Collart and Didier RaoultEmail author BMC Infectious Diseases20077:30 DOI: 10.1186/1471-2334-7-30

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