Leptospirosis: a problem for transfusion medicine?

Leptospirosis is underdiagnosed owing to its non-specific presentation, especially in the early stages of the infection. In the present research, sera from 2368 healthy blood donors of a local blood bank were screened for the presence of leptospiral antibodies using IgM-Pk-ELISA, followed by the microscopic and macroscopic agglutination tests. Serum samples showing two positive and/or borderline results in these assays were confirmed by immunoblotting. The IgM-antibody profile was defined according to the following criteria: sera reactive to a diffuse band of molecular weight 14.8-22 kDa were considered leptospirosis positive, sera exhibiting no reactivity to this band were considered negative. Our results showed a prevalence of 1.01% positivity. There is evidence that transmission of Leptospira interrogans by blood transfusion is possible, but, to date there has been no documentation of transfusion-transmitted leptospirosis. Thus, according to the currently available information, there is no need for new bloodbanking procedures to identify possible carriers of L. interrogans.