[The Borrelia of ornithodoros in tropical Africa: value and li...

The identification of Borrelia strains isolated from ticks or relapsing fever patients is not easy. Seizing the opportunity of recent isolation of such strains from Western Africa, we tried to evaluate the interest and the limits of a method classically proposed for that aim; cross protection test in mouse. This technique is proving rather difficult to perform because of different technical reasons; the results are critical to read. In some cases, these results seem undeniable, but the observed differences in protection levels are often weak, inconstant, insufficiently reliable to constitute a diagnostic tool. So it appears important to develop other identification methods, based on molecular analysis of Borrelia DNA, which will be more subtle and more specific.