infectious diseases
Cat Scratch Disease
Introduction
Cat-scratch disease is infection caused by the gram-negative bacteriumBartonella henselae. Symptoms are a local papule and regional lymphadenitis. Diagnosis is clinical and confirmed by biopsy or serologic tests. Treatment is with local heat application, analgesics, and sometimes antibiotics. (See also Overview of Bartonella Infections ) The domestic cat, particularly kittens, is a major reservoir forB. henselae. The prevalence ofB. henselaeantibodies in US cats is 14 to 50%. Almost all patients with cat-scratch disease report contact with cats, most of which are healthy. The specific location of the organism in the cat is unclear; however, periods of asymptomatic bacteremia occur in cycles. Infection is spread to humans via a bite or scratch. The cat flea transmits infection among cats and may be the cause of disease in humans who have not had contact with cats, although this theory is unproved. Children are most often affected. 