Leishmaniasis, A Simple Guide To The Condition, Diagnosis, Treatment And Related Conditions

This book describes Leishmaniasis, Diagnosis and Treatment and Related Diseases
Leishmaniasis is a parasitic infection caused by a trypanosomatid protozoan named Leishmania, a one-celled organism.
There are 3 different forms of Leishmaniasis:
1.Cutaneous - affects the skin
2.Mucocutaneous - affects the skin and mucous membranes
3.Visceral (Systemic) - affects the entire body
21 species of the protozoa are believed to cause disease in humans.
The main hosts are vertebrates often humans, rodents, canids and hyraxes.
The disease is transmitted by the bite of infected female phlebotomine sand-flies
A life cycle diagram taken from Wikipedia shows the transmission of the protozoan Leishmania from the sandfly to human.
Only the female sand-fly (Phlebotomus in the Old World and Lutzomyia in the New World) spreads the protozoan through its bite.
The flagellated promastigotes are passed out through a bite (1000 parasites per bite) into the blood of the human or animal some of the flagellates are killed while others go into the intracellular lysosomal organelles of macrophages of the reticuloendothelial system, where they drop their flagella and transform into the amastigote form.
The amastigote forms also proliferate by binary fission, with multiplication persisting until the macrophagel is filled with the parasites and bursts, freeing the amastigotes into the circulation.
The free amastigotes then attack fresh cells, thus replicating the cycle and, in the process, infecting the complete reticuloendothelial system.
Some of the free amastigotes are sucked by the sand-fly during its blood meal, finishing the cycle.
Dependent on the species of parasite and the host's immune status, the parasites may grow for weeks to months before manifesting as skin lesions or as a disseminated systemic infection affecting the liver, spleen, and bone marrow.
Infections may recover spontaneously or may go on to chronic disease, often causing death from secondary infection.
Cases of leishmaniasis have been documented on all continents except Australia and Antarctica.
Symptoms:
1.Night sweats weakness and anorexia, which are typical.
2.Fever.
3.Weight loss.
4.Hepatomegaly (can be marked).
5.Splenomegaly (often enormous).
6.Anemia and pancytopenia (can cause death from hemorrhage or infection).
7.Hyper-gammaglobulinemia.
8.Dark pigmentation of the skin is infrequent but the name kala azar is Hindi for black fever.
Diagnosis:
Tests that may be done to diagnose the disorder are:
1.Biopsy of the spleen and culture
2.Bone marrow biopsy and culture
3.Direct agglutination assay
4.Indirect immunofluorescent antibody test
5.Leishmania-specific PCR test
6.Liver biopsy and culture
7.Lymph node biopsy and culture
8.Montenegro skin test (not approved in the United States)
9.Skin biopsy and culture
Treatment:
Leishmaniasis is a treatable disease that can be cured.
The treatment is dependent upon type of disease, parasite species and geographical site.
In VL the prognosis is so much poorer so treatment is required.
For VL, new medications, switching of treatment, and the possibility for combinations of reputable drugs have improved treatment in India, but not in East Africa.
In the CL types that recover by itself the question is whether any treatment should be given, particularly as treatment can be quite toxic.
New World (West) CL may go on to mucocutaneous disease and so should be sufficiently treated.
Old World (East) CL may be left alone or treated if lesions take a longer time to recover or disfiguring
Medicines with antimony-containing compounds are the main drugs utilized to treat leishmaniasis.
New drugs that may be used are:
1.Amphotericin B
2.Miltefosine
3.Paromom

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