Rocky Mountain Spotted Fever and Other Spotted Fever Group Rickettsioses

Rickettsioses, caused by members of the typhus group and spotted fever group (SFG) rickettsiae, are significant, underrecognized diseases found worldwide. Rocky Mountain spotted fever (RMSF) was first described in the 1890s, and researchers have worked to characterize its manifestations, develop effective therapeutics, examine the biological aspects of the agent, and in particular to understand its survival and multiplication within its arthropod host. As this chapter deals primarily with human health and tick-borne SFG rickettsiae described in North, Central, and South America, the majority of the content is in reference to Rickettsia rickettsii. Furthermore, because a number of excellent reviews have been published regarding the biology of Rickettsia, the various aspects of RMSF, including issues of ecology and clinical characteristics, the chapter aims to expand on that base of knowledge and update the reader on the current trends of research on tick-borne rickettsioses.