🦠 Chapter 329 · Cryptosporidium, Cystoisospora, Cyclospora, & Microsporidia

Nelson Textbook of Pediatrics 22nd Edition | These coccidian parasites and microsporidia (reclassified as fungi) cause diarrheal illness, especially in immunocompromised hosts. Cryptosporidium (oocysts resistant to chlorine) → watery diarrhea, self-limited in immunocompetent, chronic in HIV (CD4 <100). Cystoisospora & Cyclospora → treat with TMP-SMX. Microsporidia → Enterocytozoon bieneusi (most common) and Encephalitozoon intestinalis; treatment with albendazole (for Encephalitozoon) and fumagillin (investigational). Key prevention: hand hygiene, avoid untreated water, and immune reconstitution (cART) in HIV.