Identification of rickettsial pathogens in ixodid ticks in northern Senegal.

The spotted fevers, caused by the Rickettsia bacteria, are a group of emerging diseases that are responsible for significant human morbidity. In Africa, the distribution of different species of Rickettsia in their tick vectors is poorly studied. We have collected 1169 hard ticks from 5 different species in the northern Senegal, close to the Saharan border. In a far northern collection site, corresponding to the Rickettsia africae distribution area, we collected three Amblyomma variegatum ticks infected by R. africae. Rickettsia africae was also identified in a Hyalomma marginatum rufipes tick, which may represent the secondary host for the pathogen. Rickettsia aeschlimannii was identified in H. m. rufipes, Rhipicephalus evertsi evertsi, and Hyalomma impeltatum ticks.