Visceral Leishmaniasis
Visceral Leishmaniasis is also known as Kala-azar (Indian
sub-continent). Parasite transmission occurs through female Phlebotomine’s (sand fly’s) bite.
Patients die within months
Mostly all clinically symptomatic (non-immune) patients tend to die within months if the disease is left untreated. Infected partially immune human carriers act as reservoir for the infection. Some mammals (Canids- domesticated/wild) also act as additional zoonotic reservoirs of infection (generally L. infantum).
Types of VL
2 types
VL are of 2 types:
Zoonotic VL transmitted from animals to vector to humans. Animals act as occasional hosts (mainly dogs).
Anthroponotic VL from humans to vector to humans.
Depends on the geographical area
Caused by two leishmanial species
L. donovani infects mostly children and immunosuppressed individuals
L. donovani sensu stricto affects the East Africa and Indian sub-continent.
L. infantum (L. chagasii) infects individuals of all age groups.
L. infantum affects the areas of Europe, North Africa and Latin America and the Mediterranean region.
Why more prevalent?
Three main factors for increased VL
Migration
Lack of control measures
HIV–VL co-infection driving the increased incidence of VL
Symptoms
Splenomegaly Enlargement of spleen (increase in weight and size).
Irregular fever
Anaemia deficiency of red blood cells or haemoglobin in blood, resulting in pallor and weariness.
Pancytopaenia Low blood count (of all three cells- red blood cells, white blood cells and platelets).
Weight loss and weakness occurs progressively over a period of weeks/months.
Hypersplenism peripheral destruction of erythrocytes in the enlarged spleen and bleeding (sometimes).