Vasculitis: Endothelial Dysfunction During Rickettsial Infection

Abstract

Rickettsial infections cause irreversible damage to the human host and are associated with a high morbidity and high mortality. The mortality rate can be as high as 20 % for Rocky Mountain spotted fever and 30 % for epidemic typhus, which are both diseases that are caused by rickettsiae. Some rickettsiae species, such as Rickettsia prowazekii and Rickettsia rickettsii, are currently considered bioterrorism agents. The study of rickettsiae organisms is fascinating due to the nature of these pathogens, which are obligate intracellular bacteria, and to their tropism for the endothelium. The endothelium plays a key role in numerous physiological processes, such as vascular homeostasis, the regulation of blood flow and vascular tone, coagulation, angiogenesis and inflammation. In this chapter, we give a general overview of rickettsial diseases, the endothelium, and how rickettsial infection impacts endothelial function. Specifically, we focus on the endothelial cell response to rickettsial infections and emphasize the role of the endothelial cells in the clinical symptoms and tissue injury caused by rickettsioses.