Clinical syndromes associated with infection with Taenia species tapeworms include intestinal disease caused by adult parasites (i.e., taeniasis) and single or multiorgan inflammatory conditions associated with larval stages within tissue (i.e., cysticercosis and coenurosis). Distinguishing morphologic features of adult tapeworms…
Diphyllobothriidae Description of the Pathogens Pseudophyllidean cestodes in the family Diphyllobothriidae can cause intestinal tapeworm infections in humans. Around 16 species have been reported to cause human infections, though only six species have been confirmed with modern molecular techniques. In…
Human filariasis encompasses parasitic infections caused by several species of tiny, thread-like nematode worms that affect the skin, lymphatic vessels, and connective and subcutaneous tissues. Although rarely a direct cause of death, some filarial worms, especially the three species causing…
Tissue nematodes are parasitic roundworms that invade human tissues. Many of these nematodes are present in outdoor environments and are transmitted to children through the ingestion of nonfood substances. Most of these tissue parasites are zoonoses, with the infectious stage…
Intestinal nematode infections are caused by a group of helminths, sometimes referred to as soil-transmitted nematodes, soil-transmitted helminths, or geohelminths. They are among the most common parasitic infections in humans and affect more than one-seventh of the world’s population. In…
Organisms of the genus Trypanosoma are flagellated protozoan parasites that inhabit the blood and tissue of a wide variety of vertebrate hosts, including birds, reptiles, and mammals. The name is derived from the Greek, trypano (meaning auger, a helical shaped…
Trichomonas vaginalis can infect both men and women and is recognized as the most common nonviral sexually transmitted infection in the world. Description of The Pathogen T. vaginalis , a flagellated protozoan parasite, was first described in 1836 by French…
Toxoplasma gondii , a parasite with worldwide distribution, is responsible for a significant disease burden in humans. Primary infection can be asymptomatic, mildly symptomatic with a mononucleosis like illness and/or lymphadenopathy, or it can cause severe ocular disease, even in…
Sarcocystis species are zoonotic protozoan parasites of the phylum Apicomplexa. Since its first description in 1843, >150 species have been reported from a range of wild and domestic mammals, birds, and reptiles. The organism requires a definitive host and an…
Acknowledgment Paul M. Arguin is acknowledged for substantial contributions to this chapter in previous editions. Although malaria is a major cause of morbidity and mortality in the world, most cases in the United States and Europe occur in people who…