Tick-Borne Rickettsioses around the World: Emerging Diseases Challenging Old Concepts

Unité des Rickettsies, CNRS UMR 6020, IFR 48, Université de la Méditerranée, Faculté de Médecine, 13385 Marseille Cedex 5, France.
Clinical Microbiology Reviews (Impact Factor: 17.41). 11/2005; 18(4):719-56. DOI: 10.1128/CMR.18.4.719-756.2005
Source: PubMed


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.

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    • "Since the beginning of the 20th century, ticks (Acarina), fleas (Siphonaptera) and other hematophagous arthropods have been implicated as vectors, reservoirs, and/or amplifiers of agents of human zoonoses [1]. Ticks are hematophagous arthropods that are considered second vectors (after mosquitoes) of human disease and the most significant vectors of disease-causing pathogens in animals [2, 3] . "
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    • "Dogs are considered to be the sentinels of R. conorii infection (Parola et al., 2005; Ortuño et al., 2009), which is the causative agent of Mediterranean spotted fever (MSF), one of the oldest-recognized vector-borne infectious diseases. It is transmitted by the brown dog tick, Rh. sanguineus s.l. "
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