Amastigotes of Leishmania are spherical to ovoid and measure 1-5 µm long by 1-2 µm wide. They possess a large nucleus, a prominent kinetoplast, and a short axoneme, the last of which is rarely visible by light microscopy. The organisms reside in macrophages of the host and can be found throughout the body.
What is the role of microscopy in the workup of leishmaniasis?
Light-microscopic examination of a stained bone marrow specimen from a patient with visceral leishmaniasis—showing a macrophage (a special type of white blood cell) containing multiple Leishmania amastigotes (the tissue stage of the parasite).
What type of lipophosphoglycan is produced by Leishmania amastigotes?
Intracellular amastigotes of Leishmania major produce 6 x 10 (4) copies/cell of a lipophosphoglycan (LPG) that is structurally distinct from the LPG produced by the extracellular promastigote form of L. major, Leishmania donovani, and Leishmania mexicana (reviewed by McConville, M. J. (1991) Cell Biol. Int. Rep. 15, 779-798).
What are the clinical syndromes of human leishmaniasis?
Human Leishmaniasis encompasses multiple clinical syndromes, most notably visceral, cutaneous, and mucosal forms. Infections can result in two main forms of disease, cutaneous leishmaniasis and visceral leishmaniasis (kala-azar). Different species can be associated with diverse clinical manifestations and sequelae.
What are the advantages of molecular approaches to the diagnosis of leishmaniasis?
Molecular approaches have the potential to be more sensitive and rapid; e.g., the results can be available within days versus weeks. CDC has incorporated molecular methods in the algorithm for the laboratory diagnosis of leishmaniasis.
What are the signs and symptoms of cutaneous leishmaniasis?
Cutaneous leishmaniasis is characterized by one or more cutaneous lesions on areas where sandflies have fed. Persons who have cutaneous leishmaniasis have one or more sores on their skin. The sores can change in size and appearance over time.
Where is visceral leishmaniasis Most commonly found?
Most of the affected countries are in the tropics and subtropics. The settings in which leishmaniasis is found range from rain forests in Central and South America to deserts in West Asia. More than 90 percent of the world’s cases of visceral leishmaniasis are in India, Bangladesh, Nepal, Sudan, and Brazil.
