Muscle larvae of Trichinella spiralis
(Enoplea: Trichurida)

Definitive hosts: this species infects a wide variety of mammals, including humans; carnivores and scavengers are most commonly infected Site of infection: adults in small intestine; larvae encysted within nurse cells in skeletal muscles Typical size: adult males about 1.5 mm in length; adult females about 3 mm in length Distribution: cosmopolitan