Leishmania donovani in blood smears of asymptomatic persons.

Leishmania amastigotes have been detected in the peripheral blood smears of Indian kala-azar patients mostly during night. It was, therefore, thought worthwhile to find out whether such amastigotes could be shown in healthy subjects who did not have any symptoms by history or signs on clinical examination. Leishmania-stained blood smears of 450 asymptomatic healthy individuals residing in an endemic village in Bihar (India) were examined by oil-immersion microscopy for the detection of amastigote, six people (1.3%) showed the presence of Leishmania amastigotes. Given the low sensitivity of a single smear examination it is likely that a much greater proportion of asymptomatic persons had parasitemia than the observed 1.3%. This finding is important from the point of view of transmission of disease, as also for modifying the current control measures.