Fig. 1
From: Haemoproteus minutus is highly virulent for Australasian and South American parrots
The heart and gizzard muscle of a two months old superb parrot (Polytelis swainsonii) that succumbed to disease showed severe infection with megalomeronts (arrows) of Haemoproteus minutus. Multifocally extended haemorrhages are readily visible in the heart muscle (a) and gizzard muscle (d) associated with megalomeronts (e) in this parrot. Numerous roundish megalomeronts in different stages of growth (b), each covered with a prominent capsular-like wall (c, which is an insert of b) disrupt the architecture of the heart muscle in a two weeks old Princess parrot (Polytelis alexandrae). Note the lack of a cellular host immune response towards the parasite. Imprint of gizzard muscle haemorrhages (f) associated with disrupted megalomeronts; e shows mixture of erythrocytes with syncytia originated from ruptured megalomeronts (f). Each syncytium possesses a portion of the cytoplasm and one (white arrowhead) or several nuclei (black arrowhead). During abortive development, the syncytia are readily washed out to the circulation and provide templates for PCR amplification in the blood even if intraerythrocytic stages (gametocytes) are absent. Asterisks, host tissue hemorrhage. Haematoxylin & eosin (b, c and e) and Leishman (f) stain. Scale-bars: b and e 200 μm; f 10 μm