Diurnal periodicity in peripheral parasitemias in ducklings (Anas boschas) infected with Leucocytozoon simondi Mathis and Leger

Abstract

The peripheral parasitemias of 19 naturally infected ducklings were determined at 2-h intervals from 0800 h of one day through 0800 h of the next day. A diurnal periodicity in parasitemia of L. simondi was clearly established, and was characterized by peak, densities during the daylight hours, and relatively low numbers of gametocytes at night. Gametocytes were localized in the liver, but not in the heart, when the peripheral parasitemias were low. Explanations for the diurnal fluctuations in parasitemia are advanced. The most prominent feeding period of the vector, Simulium rugglesi, coincided with the period of elevated parasitemia in the avian host.