Molecular identification of Borrelia crocidurae in a patient returning from Senegal.

Borrelia spp. are pathogens responsible for worldwide tickborne relapsing fever (TBRF). In West Africa, TBRF is due to a single species, Borrelia crocidurae, transmitted by the soft-body tick Ornithodoros sonrai. We report a case of B crocidurae infection in a French tourist in Senegal, diagnosed by molecular biology using 16S rDNA, flaB, and the 16S-23S intergenic spacer. We found six imported cases reported in travellers (since 1999). We review here clinical and molecular aspects and pathophysiology, and discuss diagnostic methods and therapeutic regimens. In the coming years, this emerging disease will be of concern to more and more travellers returning from disease-endemic regions. Thus, physicians must be aware of its presentation and diagnosis, since the spontaneous outcome can be severe, and a simple treatment is effective.