Kawasaki disease: is it caused by an infectious agent?

Kawasaki disease (KD) is an acute systemic febrile illness of unknown aetiology, predominantly affecting children under five years of age. Initially described in 1967 by Tomisaku Kawasaki, it is now the most common cause of acquired heart disease in children in the developed world. Although normally self-limiting, KD is associated with a range of complications, the most important of which is the development of life-threatening coronary artery abnormalities. Here, we examine the evidence supporting the concept that KD is caused by an infectious agent. Various infectious agents--including bacterial, viral and Rickettsial organisms--have been implicated as potential causes, as have certain immunological agents such as bacterial toxin-mediated superantigens, allergens such as anionic detergents and house-dust mites, and some chemicals (including heavy metals). Following extensive research, however, no links between any of these individual agents and the disease have been established irrefutably. Despite this, most of the epidemiological and immunological evidence currently available indicates that the causative agent is most likely to be infectious in nature; and additional evidence highlights the likelihood that development of KD is multifactorial in nature, requiring certain genetic and immunological factors, and possibly a vector.