Serological and molecular investigation of cutaneous leishmaniasis in healthy individuals from an American Cutaneous Leishmaniasis-endemic region

Abstract

American Cutaneous Leishmaniasis (ACL) is a major, clinically relevant zoonosis in Brazil. The disease spectrum includes single, localized, cutaneous ulcers, diffuse cutaneous leishmaniasis and mucosal disease. A subclinical form of the disease has also been described in individuals living in ACL-endemic regions. The goal of this study was to employ immunological and molecular diagnostic methods to evaluate the presence of subclinical ACL in healthy individuals from an ACL-endemic region in northwestern Paraná. Antibodies IgG were detected by enzyme-Linked Immunosorbent Assay (ELISA) and the positive samples were analyzed by indirect Immunofluorescence (IIF) for Leishmania braziliensis and Trypanosoma cruzi. Polymerase Chain Reaction (PCR), employing the MP3H/MP1L primers, amplified a fragment of Leishmania (Viannia) k-DNA. Of the 159 individuals analyzed, 31 presented ELISA-positive serology and 5 and 8 of these were IIF-positive for Leishmania and T. cruzi, respectively. All 159 individuals were PCR-negative. Most ELISA-positive individuals were males and the cities São Jorge do Ivaí and Doutor Camargo showed the highest prevalence of positive individuals. Our results reveal the presence of subclinical Leishmania infections in inhabitants of this region. Further investigation of this population may contribute to understanding the immune responses to ACL.