Vet. Res. 36 (2005) 469-492
DOI: 10.1051/vetres:2005004

Tick- and flea-borne rickettsial emerging zoonoses

Philippe Parola^a, Bernard Davoust^b and Didier Raoult<sup>a

a</sup>  Unité des Rickettsies, CNRS UMR 6020, IFR 48, Faculté de Médecine, Université de la Méditerranée, 13385 Marseille Cedex 5, France
^b  Direction Régionale du Service de Santé des Armées, BP 16, 69998 Lyon Armées, France

(Received 30 March 2004; accepted 5 August 2004)

Abstract - Between 1984 and 2004, nine more species or subspecies of spotted fever rickettsiae were identified as emerging agents of tick-borne rickettsioses throughout the world. Six of these species had first been isolated from ticks and later found to be pathogenic to humans. The most recent example is Rickettsia parkeri, recognized as a human pathogen more than 60 years after its initial isolation from ticks. A new spotted fever rickettsia, R. felis was also found to be associated with fleas and to be a human pathogen. Similarly, bacteria within the family Anaplasmataceae have been considered to be of veterinary importance only, yet three species have been implicated in human diseases in recent years, including Ehrlichia chaffeensis, the agent of human monocytic ehrlichiosis, Anaplasma phagocytophilum, the agent of human anaplasmosis (formerly known as "human granulocytic ehrlichiosis agent", E. equi and E. phagocytophila), and finally Ehrlichia ewingii, which causes granulocytic ehrlichiosis in humans. We present here an overview of the various tick- and flea-borne rickettsial zoonoses described in the last 20 years, focusing on the ecological, epidemiological and clinical aspects.

Key words: ticks / fleas / Rickettsia / Anaplasma / zoonoses

Corresponding author: Didier Raoult Didier.raoult@medecine.univ-mrs.fr

© INRA, EDP Sciences 2005