Montage of some of the major human helminth parasites, their developmental stages, and disease pathology.

Abstract

<p>(A) Microfilaria of <i>Brugia malayi</i> in a thick blood smear, stained with Giemsa (<a href="http://www.dpd.cdc.gov/dpdx/html/frames/a-f/filariasis/body_Filariasis_mic1.htm" target="_blank">http://www.dpd.cdc.gov/dpdx/html/frames/a-f/filariasis/body_Filariasis_mic1.htm</a>); the microfilaria is about 250 µm in length. (B) Patient with lymphedema of the left leg due to lymphatic filariasis (<a href="http://www.cdc.gov/ncidod/dpd/parasites/lymphaticfilariasis/index.htm" target="_blank">http://www.cdc.gov/ncidod/dpd/parasites/lymphaticfilariasis/index.htm</a>). (C) Hookworm egg passed in the stool of an infected person; the microscopic egg, barrel-shaped with a thin wall, is about 70×40 µm in dimension. (D) longitudinal section through an adult hookworm attached to wall of small intestine, ingesting host blood and mucosal wall. The parasite is about 1 cm in length. (E) Eggs of <i>Schistosoma mansoni</i>. The egg is about 150×50 µm in dimension; the lateral spine is diagnostic for <i>S. mansoni</i> in comparison to the other human schistosome species. Fibrotic responses to schistosome eggs trapped in the intestines, liver, and other organs of the infected person are the cause of the schistosomiasis pathology and morbidity. (F) A pair of adult worms of the blood fluke <i>Schistosoma mansoni</i>; the more slender female worm resides in the gynecophoral canal of the thicker male. The worms are about 1.5 cm in length, and live for many years (<a href="http://www.dpd.cdc.gov/dpdx/HTML/ImageLibrary/Schistosomiasis_il.htm" target="_blank">http://www.dpd.cdc.gov/dpdx/HTML/ImageLibrary/Schistosomiasis_il.htm</a> ).</p