KALA AZAR Leishmaniasis is a disease caused by protozoan parasites of to the genus Leishmania and is transmitted by the bite of sand fly. This disease is also known as kala azar, black fever, sandfly disease, Dum-Dum fever. Human infection is caused by about 21 of 30 species that infect mammals. These include the L. donovani complex with three species (L. donovani, L. infantum, and L. chagasi

Epidemiological features Agents: Leishmania donovani is the causative agent of kalazar, L. tropica is the causative agent of cutenous leishmaniasis and L. braziliensis is the causative agent muco cutenous leishmaniasis. Reservoir of infection: There are variety of animal reservoirs, e.g. dogs, jackals, foxes, rodents.

Cont.. Age: Kala-azar can occur in all age groups including infants below the age of one year. Sex: Males are affected twice than female. Environmental factors: kala-azar is mostly confined to plains, it does not occur in altitudes over 2000 feet. Sand flies breed in cracks and crevices in the soil and buildings, tree holes, caves etc. Overcrowding and ill-ventilation and accumulation of organic matter in the environment facilitate transmission.

Cont.. Mode of Transmission: It is transmitted from person to person by bite of female phlebotomine sandfly. Transmission may also take place by contamination of the bite wound. Incubation Period: The incubation period in man is quite variable, generally 1-4 months, about 10 days to 2 years.

Atypical features of the disease, lymphadenopathy may occur. Signs and symptoms Kala azar: The classical feature of kala azar are fever, splenomegaly, hepatomegaly accompanied by anaemia and weight loss. Darkening of the skin of face, hands, feet and abdomen. Atypical features of the disease, lymphadenopathy may occur. Kala azar if left untreated, has a high mortality.

Four main forms of leishmaniasis: Visceral leishmaniasis (kala azar) - the most serious form and potentially fatal if untreated. Cutaneous leishmaniasis - the most common form which causes a sore at the bite site, which heal in a few months to a year, leaving an unpleasant looking scar. This form can progress to any of the other three forms.

Cont.. Diffuse cutaneous leishmaniasis - this form produces widespread skin lesions which resemble leprosy and is particularly difficult to treat. Mucocutaneous leishmaniasis - commences with skin ulcers which spread causing tissue damage to (particularly) nose and mouth

Diagnosis Parasitological diagnosis: The demonstration of parasites LD bodies in the aspirates of the spleen, liver, bone marrow, lymph nodes or in the skin is the only way to confirm VL and CL conclusively. The parasite must be isolated in culture to confirm the identity of the parasite. Haematological findings: anaemia, leucopenia, increased ESR.

Prevention and control Early detection of the cases and treatment. Sandfly control Personal prophylaxis. Treatment: Pentavalent antimony compounds are use to treat kalazar. The recommended schedule is daily injection given IV or IM of sodium stibogluconate, 10 mg/ kg body weight. Amphotericin is now the treatment of choice

Cont.. Sandfly control: The application of residual insecticides has proved effective in the control of sand flies. DDT is the first choice. Insecticide spraying should be undertaken in human dwellings, animal shelters. Spraying should be repeated at regular intervals to reduce sand flies.

Cont.. Personal prophylaxis: The risk of infection can be reduced through health education and by use of individual protective measures such as avoiding sleeping on floor, using mosquito nets. Insect repellants( in the form of lotions, creams) for temporary protection and keeping the environment clean.