[African Rickettsia infections].
EPIDEMIOLOGY
African rickettsiasis is transmitted by Rickettsia africae, a cattle tick. Amblyomma spp. is an emerging rickettsiasis in sub-sehalian Afric described in 1992. Seroepidemiology studies conducted in Africa show that it is probably the most widespread rickettsiasis in the sorld. In addition, the development of tourist activities in southern African countries has led to an increase in the number of reported cases in subjects returning from endemic areas. A high serprevalence of anti R. africae anticodies has been recently reported in the guadeloupe (French East Indies) population as well as one documented infection.


CLINIC
The clinical expression of African tick rickettsiasis includes fevder, headache, inoculation scar, locoredgional node enlargement, and an inconsistent sometimes vesicular rash. The diagnosis is made on the basis of serological findings and cross absorption of anti R. africae and R. conorii antibodies and/or isolation or gene amplification of R. africae from inoculation scar biopsies.