Where is Leishmania most common?
In what parts of the world is leishmaniasis found? In the Old World (the Eastern Hemisphere), leishmaniasis is found in some parts of Asia, the Middle East, Africa (particularly in the tropical region and North Africa, with some cases elsewhere), and southern Europe. It is not found in Australia or the Pacific Islands.
What is the most common form of leishmaniasis?
The most common forms are cutaneous leishmaniasis, which causes skin sores, and visceral leishmaniasis, which affects several internal organs (usually spleen, liver, and bone marrow).
Which host are Leishmania amastigotes found in?
Leishmania parasites are dimorphic organisms that live and replicate in the gut of sandflies as flagellated forms (promastigote) or as aflagellated forms (amastigotes) in mammalian cells. In the mammalian host these parasites preferentially infect phagocytic cells, primarily macrophages and dendritic cells.
Which disease is caused by protozoa Leishmania?
Leishmaniasis is a vectorborne disease that is transmitted by sand flies and caused by obligate intracellular protozoa of the genus Leishmania.
Which is the most common reservoir for the Leishmania protozoan?
The reservoir of infection for Indian kala-azar is humans, whereas it is rodents for African kala-azar, foxes in Brazil and Central Asia, and canines for the Mediterranean and Chinese kala-azar. Other mammalian reservoirs for the Leishmania parasite include equines and monkeys.
Where are sandflies found?
Adult sand flies often inhabit rock crevices, caves, and rodent burrows, and in peri-domestic settings rest in cool, dark and humid corners of animal shelters or human dwellings [22] [24].
Which type of leishmaniasis is most likely fatal?
Visceral leishmaniasis (VL), also known as kala-azar is fatal if left untreated in over 95% of cases.
What is the vector of Leishmania spp?
The leishmaniases are a group of vector-borne diseases caused by a protozoan parasite from the genus Leishmania and transmitted through the bite of infected female sandflies. The only proven vectors of human disease are species and subspecies of Phlebotomus in the Old World and Lutzomyia in the New World.
Where do Leishmania amastigotes transform Promastigotes?
abdominal midgut
(K) Amastigotes form “nest cells” in the abdominal midgut. (L) Amastigotes transform into procyclic promastigotes. (M) Promastigotes multiply and attach to the midgut epithelium. (N) Parasites migrate toward the anterior midgut, resume replication and start to produce promastigote secretory gel (PSG).
Which diseases are commonly caused by protozoa?
Common protozoan infectious diseases include malaria, giardia, and toxoplasmosis. Less common diseases include African trypanosomiasis and Amoebic dysentery. Each condition affects the body differently.
What is the reservoir of Kala-azar?
What is the structure of Leishmania amastigotes?
Leishmania amastigotes live and multiply within macrophages by binary fission. They are round or ovoid bodies, approximately 2 to 3 µm in diameter. Occasional rupture of cells allows invasion of uninfected monocytes and macrophages by free forms.
How do you identify Leishmania promastigotes from culture?
Figure A: Leishmania sp. promastigotes from culture. In the human host, only the amastigotes stage is seen upon microscopic examination of tissue specimens. Amastigotes can be visualized with both Giemsa and hematoxylin and eosin (H&E) stains.
What are the characteristics of leishmaniasis?
Leishmaniasis 1 Causal Agent. Leishmaniasis is a vector-borne disease that is transmitted by sandflies… 2 Life Cycle. Leishmaniasis is transmitted by the bite of infected female phlebotomine sandflies. 3 Geographic Distribution. Leishmaniasis is found in parts of about 88 countries.
How is Leishmania tropica amastigotes (arrows) characterized in biopsy?
Figure C: Leishmania tropica amastigotes from an impression smear of a biopsy specimen from a skin lesion. In this figure, an intact macrophage is practically filled with amastigotes (arrows), several of which have a clearly visible nucleus and kinetoplast. Leishmania mexicana in tissue stained with hematoxylin and eosin (H&E).