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Why can visceral leishmaniasis cause an enlarged liver and spleen?
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parasitic disease
Trypanosoma brucei in a blood smear (Giemsa-stained light photomicrograph).
Visceral leishmaniasis, also known as kala-azar, causes an enlarged liver and spleen because the causative parasitic protozoan (such as Leishmania donovani) specifically targets and proliferates within the macrophages of these organs, as well as the bone marrow.123
As the parasites multiply within these immune cells, the resulting infection leads to systemic inflammation and the characteristic enlargement of the liver and spleen. This condition is a severe, systemic form of leishmaniasis that is typically fatal if left untreated.13