Interest in the rickettsial agents and diseases is growing because of increased resistance to the standard antibiotic treatments and because of their potential for being used as biological weapons. Discoveries of "new " rickettsioses will help us better understand the ones we've been aware of for decades. The pathogens and diseases discussed in this volume include Coxiella burnetti (Q fever, a potential category B biological weapon), Bartonella spp., Ixodes ovatus ehrlichia, Rickettsia Rickettsii (Rocky Mountain spotted fever), Rickettsia conorii conorii, Ehrlichia chaffeensis, Orientia tsutsugamushi (scrub typhus), and Rhipicephalus sanguineus (Mediterranean spotted fever). The glycomics, proteomics, ecology, and global epidemiology of rickettsial diseases is discussed with particular mention of rickettsial diseases in North, Central, and South America; Australia; North Africa; Australia; and Thailand.