Cat-scratch disease is an infection with bartonella bacteria that is believed to be transmitted by cat scratches, cat bites, or flea bites.
CSD; Cat-scratch fever; Bartonellosis
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.
A person who has had contact with an infected cat may show common symptoms, including:
Bump (papule) or blister (pustule) at site of injury (usually the first sign)
Sometimes, an infected lymph node may form a tunnel (fistula) through the skin and drain (leak fluid).
This disease is often not found because it is hard to diagnose. The Bartonella henselae immunofluorescence assay (IFA) blood test is an accurate way to detect the infection caused by these bacteria. The results of this test must be considered along with other information from your medical history, lab tests, or biopsy.
Generally, cat-scratch disease is not serious. Medical treatment may not be needed. In some cases, treatment with antibiotics such as azithromycin can be helpful. Other antibiotics may be used, including clarithromycin, rifampin, trimethoprim-sulfamethoxazole, or ciprofloxacin.
In people with HIV/AIDS and others, who have a weakened immune system, cat-scratch disease is more serious. Treatment with antibiotics is recommended.
People who have a healthy immune system should recover fully without treatment. In people with a weakened immune system, treatment with antibiotics usually leads to recovery.
People whose immune systems are weakened may develop complications such as:
Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.