Asymptomatic Leishmania infantum infection in blood donors living in an endemic area, northeastern Italy

Objectives: Human leishmaniasis can be severe and fatal, yet in the Mediterranean region only a small percentage of infections progress to clinical disease. We evaluated the percentage of asymptomatic Leishmania infection in the Bologna province, northeastern Italy. Methods: We examined the presence of specific antibodies by Western Blot (WB) and parasitic DNA by real time PCR in peripheral blood of 240 blood donors residing in the Bologna province. Results: Anti-Leishmania IgG were detected by WB in 27 subjects (11.2%, 95% CI 7%-15%), while Leishmania kinetoplast DNA was detected in peripheral blood specimens of 4 out of 240 donors (1.7%, 95% CI 0.2%-3.2%). Overall, the prevalence of Leishmania infection in the blood donor cohort was 12.5%, thus indicating an elevated cumulative exposure to the Leishmania parasite in the examined municipality. Conclusions: Our results suggest that a surveillance system for monitoring Leishmania infection in blood donors and/or strategies of protozoan inactivation in whole blood should be taken into consideration in areas with circulation of the Leishmania parasite.