Immunoperoxidase method of identification of Leishmania in routinely prepared histological sections

An indirect immunoperoxidase technique was applied for identification of Leishmania in routinely prepared histological sections. Paraffin embedded, formalin-fixed slide preparations of skin (1 case), bone marrow (2 cases) and lymph node (1 case) were examined. The tissues were obtained from one patient with cutaneous leishmaniasis and from three patients with visceral leishmaniasis. Specific rabbit antisera against L. donovani, L. tropica and L. mexicana were used as primary reagents. Positive controls were performed simultaneously and included L. tropica cultures in blood-agar (NNN media) - free promastigotes and amastigotes within macrophages. Strongly positive brown staining was localized specifically in Leishman-Donovan (LD) bodies only. This method increases the probability of microscopic diagnosis of leishmaniasis and helps to prevent confusion of Leishmania with other infective agents in histological sections.