RT Book, Section A1 Barroso II, Luis F. A1 Guerrant, Richard L. A2 Rudolph, Colin D. A2 Rudolph, Abraham M. A2 Lister, George E. A2 First, Lewis R. A2 Gershon, Anne A. SR Print(0) ID 7031562 T1 Chapter 345. Cryptosporidiosis T2 Rudolph's Pediatrics, 22e YR 2011 FD 2011 PB The McGraw-Hill Companies PP New York, NY SN 978-0-07-149723-7 LK accesspediatrics.mhmedical.com/content.aspx?aid=7031562 RD 2024/04/19 AB Cryptosporidium species are tiny (2–6 μm), obligate intracellular parasites related to other coccidian protozoan, including Toxoplasma, Cyclospora, Isospora, Plasmodium, Eimeria, and Sarcocystis.Cryptosporidium species primarily infect the gastrointestinal tract of a variety of vertebrate hosts, including humans.1 Host range is largely a function of species, as a given species of parasite most efficiently maintains infection within a few species of hosts.