TY - CHAP M1 - Book, Section TI - Parasites—Basic Concepts A1 - Ryan, Kenneth J. PY - 2022 T2 - Sherris & Ryan's Medical Microbiology, 8th Edition AB - The discipline of Medical Parasitology encompasses a broad spectrum of organisms belonging to the kingdoms Protista and Animalia that include diverse phylogenetic groupings such as the subkingdoms Protozoa and Metazoa, respectively. The latter include the trematodes, cestodes (Platyhelminthes), and nematodes (Nemathelminthes). Although often quite dissimilar, many parasites do share some important traits. They are opportunists by nature and exploit environmental niches and lifestyles within their hosts that suit their individual needs. Many have high prevalence rates, given the right set of circumstances, and may cause significant morbidity and mortality. All have exceedingly complex life cycles. The purpose of this chapter, and Chapters 49 and 50 that follow, is to lay a foundation of basic definitions and concepts that hopefully will aid the student in better understanding the specific diseases that will be described in succeeding chapters. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/29 UR - accessmedicine.mhmedical.com/content.aspx?aid=1185635015 ER -