Parola P. auteur aut IRD Socolovschi C. auteur aut IRD Raoult Didier auteur aut IRD text journalArticle eng text/pdf born digital access Mediterranean spotted fever is the most important tick-borne disease occurring in Southern Europe and North Africa. The first case of this life-threatening zoonosis was reported in 1910. In the 1930s, the role of the brown dog tick, Rhipicephalus sanguineus, and the causative agent, Rickettsia conorii were described. However, basic questions regarding the relationships between the rickettsia and its tick vector are still unresolved, and the life cycle of R. conorii is incompletely known. There is a lack of knowledge associated with the role of Rh. sanguineus in the maintenance and transmission of R. conorii. The infectious rate of Rh. sanguineus ticks with R. conorii has been found low every time it has been tested; usually lower that 1%. The deleterious impact of R. conorii on ticks has been suggested in experimental models as a potential reason to explain a low prevalence in nature. The long-recognized phenomenon known as reactivation has been suggested as a cause of negative effects - that is, the change in temperature and physiology of the tick host induces the agent to emerge from dormancy and attain infectivity with bad effects on ticks. However, naturally infected colonies of ticks have been maintained in laboratory conditions over several generations. We discuss here several aspects that have been recently studied to better understand Rh. sanguineus-R. conorii relationships, including comparison between the fitness of infected and non-infected ticks in laboratory conditions and the role of external factors such as temperature and starvation. specialized Rhipicephalus sanguineus Rickettsia conorii ticks - rickettsia 052 1166 49-54 2009 0077-8923 https://www.documentation.ird.fr/hor/fdi:010046163 10.1111/j.1749-6632.2009.04518.x 0077-8923 [F B010046163] https://www.documentation.ird.fr/hor/fdi:010046163 https://www.documentation.ird.fr/intranet/publi/2009/07/010046163.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2009-07-24 2017-08-23 fdi:010046163 fre