These results as well as the mismatches in the primer sequences comparing with those of other representative species of blood parasites, particularly L. caulleryi, suggest that the coxIII PCR primers we used are relative specific for L. sabrazesi. To improve the sensitivity in detecting low-level infections, a nested-PCR method can be considered; however, nested-PCR is also very sensitive to laboratory contaminations because of two-round amplifications. The gene discussed is MT-CO3; the disease is infection.