Anisakiasis is an intestinal nematode, meaning that it is a
nonsegmented roundworm that invades the human gut. The Nematodes
belong to the phylum Nematoda and are relatively advanced
parasites; most are free living, have complete digestive systems
and are also sexually dimorphic. The parasite was first discovered
in the Netherlands after a nematode was surgically removed from the
mucus membrane of a patient's small intestine. Humans become
infected by consuming raw or undercooked fish containing 3rd-stage
larva. Humans can also have allergic reactions to chemicals
produced by the worm that remain in the fish flesh. Crustaceans and
small fish are reservoirs for this parasite. Larger fish (such as
herring, mackerel and salmon) vector the larva to humans. The larva
develop into adult worms inside one's stomach or small intestine.
The parasite only fully matures inside a marine mammal's
gastrointestinal tract. Symptoms include abdominal pain and nausea.
Onset of illness is 1 to 5 days after consuming contaminated
seafood. The majority of human infections are reported in Japan
(from sushi and sashimi consumption) and the Netherlands (from
pickled herring consumption). Diagnosis is made upon history of
exposure and sometimes gastroscopy or surgery. Anisakasis is not
lethal and does not usually produce acute symptoms, so no treatment
is necessary. However, 400 mg of Albendazole, twice daily for 21
days is curative.
Kingdom: Animalia
Phylum: Nematoda
Class: Secernentea
Order: Ascaridida
Family: Anisakidae
Genus: Anisakis
Species: A. pegreffii, A. physeteris, A. schupakovi, A. simplex,
A. typical, A. ziphidarum
