Tuesday, July 24, 2012

An Overview of Visceral Leishmaniasis

Visceral Leishmaniasis may sound so medical and foreign but this disease is the second most common parasitic killer in the world. It is responsible for over 500,000 new cases each year. The disease is endemic in Africa and some areas of Europe. Because of the prevalence of poverty and the difficulty to educate the people in depressed areas, campaign against leishmaniasis is not too successful. Furthermore, Africa's continuous civil war in various places made it more difficult to eradicate the disease. Because of displacement and people always travel from one place to another just to look for a better place to live in, these people unknowingly spread Leishmaniasis.
Causative Pathogen
The causative pathogen of visceral leishmaniasis was first described by Doctor William Leishman and Charles Donovan. Because of their efforts, the pathogen was named after them, Leishmania donovani.
Today, there are three species of L. donovani that were identified to cause V. leishmaniasis. These are L. donovani, L. infantum, and L. chagasi with the first two mentioned species primarily affect Africa, Europe, and Asia while the last affects South America.
L. donovani is transmitted through a vector sandfly. The sandfly is so small that it is hard to notice. Infected sandfly will suck blood from its host then through its saliva; the L. donovani crosses the body's first line of defense. The parasite will then overrides macrophages and inside, they will nourish themselves until the parasite is able to replicate itself. Eventually, the macrophage will burst, releasing the daughter parasites. They will then find new macrophages to infect and this procedure is repeated unless proper medication and management is administered. The most affected organs during L. donovani invasion are the liver and spleen.
Signs and Symptoms
Most patients dying from visceral leishmaniasis do not die because of the disease itself. In most areas where leishmaniasis is endemic, there are also other prevailing diseases. For example, AIDS is also a problem in Sudan and in some African countries. As an opportunistic infection, the crippling effect of both AIDS and leishmaniasis occurring simultaneously in one body is too much to handle by an individual. As a result, sure death is incurred. The following are some of the signs and symptoms of visceral leishmaniasis.
Decreased weight 
Enlargement of the spleen and liver 
Abnormal blood count (low WBC and platelets)

Prevention is always better than cure. As of 2012, there are efforts headed by a research institute to produce a vaccine. Trials are still on going to test the vaccine with promising results. If this vaccine is successful, then prevalence of visceral leishmaniasis will surely decrease.

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