Cat-scratch disease and the role of the domestic cat: vector, reservoir, and victim?

An unidentified coccobacillus has been implicated recently as the agent of Cat-Scratch Disease (CSD) in human beings. Although a history of close contact with a domestic cat is frequently elicited from CSD patients, the exact role of this animal in the epidemiology of the disease remains obscure. Current thinking holds that the cat merely serves as an efficient inoculator of a free-living organism. We believe that the cat is not only an important vector of the CSD bacillus, but it may also serve as the principal reservoir, with the organism occasionally present among the oral flora. Under some circumstances (e.g., immunoincompetency) the CSD bacillus may also infect the lymph nodes of cats, resulting in a disease similar to CSD in human beings.