title: Tick-borne rickettsioses around the world: emerging diseases challenging old concepts.
abstract: During most of the 20th century, the epidemiology of tick-borne rickettsioses could be summarized as the occurrence of a single pathogenic rickettsia on each continent. An element of this paradigm suggested that the many other characterized and noncharacterized rickettsiae isolated from ticks were not pathogenic to humans. In this context, it was considered that relatively few tick-borne rickettsiae caused human disease. This concept was modified extensively from 1984 through 2005 by the identification of at least 11 additional rickettsial species or subspecies that cause tick-borne rickettsioses around the world. Of these agents, seven were initially isolated from ticks, often years or decades before a definitive association with human disease was established. We present here the tick-borne rickettsioses described through 2005 and focus on the epidemiological circumstances that have played a role in the emergence of the newly recognized diseases.
authors.affiliation: Unité des Rickettsies, CNRS UMR 6020, IFR 48, Université de la Méditerranée, Faculté de Médecine, 13385 Marseille Cedex 5, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Parola
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Paddock
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
mesh_terms: D000818:Animals; D001179:Arthropod Vectors / Q000382:microbiology*; D021821:Communicable Diseases, Emerging; D004197:Disease Reservoirs; D006801:Humans; D012281:Rickettsia / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D012282:Rickettsia Infections / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D017282:Tick-Borne Diseases / Q000175:diagnosis* / Q000453:epidemiology; D013987:Ticks / Q000382:microbiology*