[Rickettsia africae, the agent of African tick-bite fever: an emerging pathogen in the West Indies and Reunion Island (Indian Ocean)].

Rickettsia africae is the agent of African tick bite fever, an emerging disease transmitted by Amblyomma ticks in sub-Saharan Africa. In 1998, we reported the first documented case of R. africae in the New World, in a patient who had returned from Guadeloupe. In order to confirm the presence of R. africae in the West Indies, entomologic surveys were conducted from 1999 to 2003 to collect Amblyomma, which are considered as potential vectors and reservoirs of the bacteria. Ticks were used as epidemiological tools to detect R. africae by molecular tools and/or cultivate the bacteria in shell-vial cell culture. This paper summarizes the results obtained in the West Indies. R. africae was detected and isolated for the first time in Guadeloupe, and then detected by molecular tools in Martinique and St-Kitts and Nevis. These last results confirm our first hypotheses--that is R. africae is prevalent on all the Caribbean islands where A. variegatum ticks have been introduced from Africa in the 18th and 19th centuries. We also present the results of a study conducted on the Reunion Island, a French island in the Indian Ocean. For the first time there, R. africae was detected in A. variegatum ticks, which were probably introduced from the African mainland or Madagascar with the human colonization during the 17th century Thus, clinicians should be aware that patient presenting in the West Indies or on Reunion Island (or after a trip over there) with fever, eschar (often multiple), regional lymphadenopathy and a rash, might be infected by R. africae.