Anisakis

Definition

Definition of Anisakis
Anisakis is a genus of parasitic nematodes, which have a life cycle involving fish and marine mammals. They are infective to humans and cause anisakiasis. People who produce immunoglobulin E (IgE) in response to this parasite may subsequently have an allergic reaction, including anaphylaxis, after eating fish that have been infected with Anisakis spp.

Morphology: Anisakids share the common features of all nematodes; the vermiform body plan, round in cross section and a lack of segmentation. The body cavity is reduced to a narrow pseudocoel. The mouth is located anteriorly, and surrounded by projections used in feeding and sensation, with the anus slightly offset from the posterior. The squamous epithelium secretes a layered cuticle to protect the body from digestive juices.

As with all parasites with a complex life cycle involving a number of hosts, details of the morphology vary depending on the host and which life cycle stage is in. In the stage which infects fish, Anisakis spp. are found in a distinctive "watch-spring coil" shape. They are roughly 2 cm long when uncoiled. When in the final host, anisakids are longer, thicker and more sturdy, to deal with the hazardous environment of a mammalian gut.

Symptoms

Symptoms of Anisakis
Consult with your doctor.

Causes

Causes of xxxxxx
Consult with your doctor.

Diagnosis

Diagnosis of Anisakis
Consult with your doctor.

Treatment

Treatment of Anisakis
For the worm, humans are a dead-end host. Anisakis and Pseudoterranova larvae cannot survive in humans, and will eventually die. In some cases, the infection will resolve with only symptomatic treatment. In other cases, however, infection can lead to small bowel obstruction, which may require surgery, although there are case reports of treatment with albendazole alone (avoiding surgery) being successful. Intestinal perforation (an emergency) is also possible.

Prognosis

Prognosis of Anisakis
Consult with your doctor.

Prevention

Prevention of Anisakis
Consult with your doctor.