Leishmaniasis Causes - How Kala-Azar Spreads?

Ayurvedic Name: Kala Jwara

Alternative Names: Kala-Azar, Black Fever, Dum Dum Fever and Black Disease, Sand fly Disease, Espundia.

What are the causes of Kala-Azar?

Leishmaniasis, one of very known infection caused by protozoan parasites of the genus Leishmania. The most common clinical presentation is localized ulcer or nodule. The infection is spread by the bite of female sand flies, which usually get infected by first biting an infected person and then inject parasites called mastigotes into the bloodstream or skin of a healthy person. The parasite migrates to the bone marrow, spleen, and lymph nodes. In endemic areas, nonhuman mammalian species serve as reservoir hosts. These parasites then reproduce, causing the symptoms.

Kala-azar infection has been reported in all continents including almost 90 countries around the world, including all the tropical and sub tropical countries and southern Europe. The only continent in which this infection has not been seen is Australia. Kala-azar is present in Iraq and was contracted by a number of the troops involved in the 2003 invasion of that country and the subsequent occupation.

Since sand flies do not make noise when they fly, people may not realize they are present. Sand flies are very small and may be hard to see, so they can attack on anyone anytime. Of note, the bite of one infected sand fly is more than enough to cause the disease, since a sand fly can ingest more than 1000 parasites per bite. They are mostly seen during the twilight, evening, and night-time hours (from dusk to dawn), and are less seen during noon. Rarely, leishmaniasis is spread from a pregnant woman to her baby. Children are at greater risk than adults in endemic areas. Kala-Azar can be easily spread by blood transfusions or contaminated needles.

Leishmaniasis (Kala-Azar) occurs mainly in two forms:

* Visceral Leishmaniasis: a chronic wasting illness also known as kala azar.
* Cutaneous Leishmaniasis: a skin disorder which results in ulceration.

Both forms of Leishmaniasis are spread by different types of sand flies.