“…This observation is consistent with the results obtained with sympatric isolates of H or murine origin from Senegal, where the analysis of isoenzymes was used (Sène et al 1997). It has been demonstrated, through the use of DNA analysis, that strains that are geographically close present homology (Pillay & Pillay 1994, Pinto et al 1997. Even the strains that are geographically different present over 90% similarity (Pillay & Pillay 1994).…”