Leishmaniasis - The History Of The Disease

Leishmaniasis is a parasitic disease which is spread by the bite of infected sand flies.

There are a number of types of protozoa like L. Donovani, L. Infantum, L. Chagasi, L. Mexicana which can cause leishmaniasis. L. chagasi, is responsible for leishmaniasis in the present generation whereas L.infantum causes the disease in the canines. People are at risk for leishmaniasis irrespective of their ages and especially susceptible if they live or travel to areas where leishmaniasis is highly prevalent.

Adventure travelers, bird watchers, researchers, peace workers and unwary holiday travelers are usually the ones to get infected. Untreated visceral leishmaniasis in a pregnant mother increases the chances of having grave consequences on the fetus or may also result in congenital visceral leishmaniasis.

The disease first came to attention of the doctors in Bangladesh when they misinterpreted it to be a variation of malaria. Leishmania is also called as kala-azar which in sanksrit means black fever. They called it black fever due to the hyper pigmentation of the skin in the abdomen and neck regions which is a common symptom of the disease. The Scottish doctors William leishman and Charles Donovan were the first to independently study and isolate the agent and publish their discoveries and hence the species name of leishmania donovani.

Kala-azar now almost directly refers to the most deadly form of leishmaniasis which is visceral. It was first endemic in west Bengal but the most virulent strains were found in Africa where it was killing thousands every year. An attack in the upper Nile region in a place called Duar left the place with four survivors out of a thousand inmates.

About 88 countries in the world in the tropics and sub-tropics are places of high risk. These places are usually areas of high tourist interest like the rain forests in Central and South America to the dry deserts in Asia. 90% of the world's cases of visceral leishmaniasis are from Asian countries like India, Bangladesh, Nepal, Sudan, and from South American countries like Brazil, Argentina, Africa and also the middle East. Leishmaniasis is not prevalent in the countries along the pacific like Australia etc

Males are found to be susceptible to the attack rather than females and there are some forms of parasites which attack children more than the adults. The disease is not continuous in its spread because the carrier agent is the sand fly. It hits hard in areas where poor nutrition, infection, and other stresses expose the affected patients to increased fear and hence higher mortality rates. Economic conditions like national emergencies, large migrating crowds, and consistent famine increase the incidence and the development of the Leishmaniasis. Out of the 350 million people living in the incident areas the disease kills around 80000 people annually.