Quantitative PCR for the diagnosis of cutaneous leishmaniasis from formalin-fixed and paraffin-embedded skin sections

The present report describes a real-time PCR-based procedure to reliably determine the quantity of Leishmania amastigotes in relation to the amount of host tissue in histological skin sections from canine and equine cases of cutaneous leishmaniasis. The novel diagnostic Leishmania-PCR has a detection limit of <0.02 amastigotes per μg tissue, which corresponds well to the detection limit of immunohistochemistry and is far beyond that of conventional histology. Our results emphasise the importance of PCR to complement routine histology of cutaneous leishmaniasis cases, particularly in laboratories in which no immunohistochemical assay is available.