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Cutaneous Leishmania

Scientific name. Leishmania tropica, Leishmania major, Leishmania aethiopica

Disease. Oriental sore, Old world cutaneous leishmaniasis

Geographic distribution. India, China, Bangladesh, Middle East, Mediterranean countries, Tropical Africa, South American countries.

Infection rate. Several ten thousands of new patients appear annually in those endemic areas.

Life cycle. Rodents are the reservoir hosts; and vectors are the sandfly (Phlebotomus spp.). In rodents, amastigotes proliferate in the cytoplasm of mononuclear phagocytic cells of the viscera or skin. When a female sandfly vector sucks blood of the infected rodents, the amastigotes enter into the vector and transform as promastigotes. As the promastigote-carrying sandflies bite rodents or humans, the promastigotes are introduced into the new hosts. They are transformed to amastigotes and invade the phagocytic cells to proliferate. Human host is infected by sandfly-biting.

Morphology. The amastigotes are small elliptical, intracellular organisms of 2-3 ㎛. It has one nucleus and one kinetoplast but not free flagellum. The promastigote has one anterior free flagellum. The bodies are 6-10 ㎛ long and 1 ㎛ wide.

Pathology and clinical symptoms. The mainly involved organ is the skin in human. A subcutaneous nodule with central necrosis is the main pathologic symptom.

Diagnosis. Detection of amastigotes by biopsy of the skin lesion confirms the diagnosis. Serology or PCR may support the diagnosis

Prevention. Protection from sandfly bite is essential.

Sung-Tae Hong