Eucestoda the "broad tapeworm" or "fish tapeworm") and related species. Humans become infected by eating raw, undercooked, or marinated fish acting as a second intermediate or paratenic host harboring metacestodes or plerocercoid larvae. Clinical symptoms are due to the large size of the tapeworm, which often reaches a length exceeding 15 m. The most common symptom is pernicious anemia, caused by the absorption of vitamin B12 by the worm. Other symptoms include various intestinal issues, slight leukocytosis, and eosinophilia. This condition is caused by the plerocercoid larvae of the tapeworm "Spirometra". Humans become infected by drinking contaminated water, eating raw or
Listeria Listeria Listeria is a genus of bacteria that, until 1992, contained 10 known species, each containing two subspecies. As of 2014, another five species were identified. Named after the British pioneer of sterile surgery Joseph Lister, the genus received its current name in 1940. "Listeria" species are gram-positive, rod-shaped, and facultatively anaerobic, and do not produce endospores. The major human pathogen in the genus "Listeria" is "L. monocytogenes". It is usually the causative agent of the relatively rare bacterial disease listeriosis, an infection caused by eating food contaminated with the bacteria. Listeriosis can cause serious illness in pregnant women, newborns,