Correlation of hyperplasia, splenomegaly and hepatomegaly with parasite population in BIO.LP-a mice infected with Leishmania donovani.

Congenic strain of BIO.LP-a male mice were experimentally infected with Leishmania donovani 3S strain from the spleen of a hamster donor. The weight ratio of spleen body, liver body and spleen liver calculated from the weight of six mice taken at weekly intervals for a period of 49 days showed that there is no hepatomegaly or splenomegaly during the first 14 days of infection when the parasite population increases. Maximum enlargement of liver and spleen was observed at day 35 postinfection, when the parasite population had declined to 11 per cent. Slight recovery was noted at day 49 with parasites reducing to 1 per cent. It is suggested that in endemic areas of human visceral leishmaniasis a search for amastigotes should be made from the biopsy of the liver or sternal puncture during the first phase of the disease when the patients suffer from a high fever with rigors. With the enlargement of liver and spleen due to proliferative response and infiltration of plasma cells, the parasite population disappears.