fish tapeworm


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Related to fish tapeworm: Diphyllobothrium latum, Pork tapeworm, Dwarf tapeworm, dog tapeworm

tapeworm

 [tāp´werm]
any parasitic worm of the subclass Cestoda; these have a flattened bandlike form and numerous species can lodge in the intestines of many animals including human beings. Tapeworms are transmitted to humans in larval form embedded in cysts, in meat or fish that is not properly cooked. In the human body they develop to maturity and attach themselves to the wall of the intestine, where they grow and release eggs. Called also cestode.



Although a large variety of adult tapeworms are sometimes human parasites, only a few infect humans to any great degree. Taenia saginata, the beef tapeworm, and T. solium, the pork tapeworm, are widespread and quite common. Beef tapeworms grow to a length of 4 to 8 meters (12 to 25 feet), and adult pork tapeworms average 2 to 4 meters (6 to 12 feet) in length. Both species release white, egg-containing proglottids, or segments of the body, which make their way to the anus and may be found in clothes or bedding. Diphyllobothrium latum, the fish tapeworm, is found in North America in the Great Lakes region, as well as in Northern Europe and Japan; it may grow as long as 18 meters (60 feet). Hymenolepis nana and H. diminuta are dwarf tapeworms that are common in the tropics and subtropics.

The diagnosis of a tapeworm infection is made when segments of the worm are found in clothing or bedding or when characteristic eggs or segments are found in the stool. Occasionally diarrhea, vague abdominal cramps, flatulence, distention, and nausea occur. Mental deterioration and seizures are rare complications, occurring only when larval forms of the worm invade brain tissue. Tapeworm infection can be prevented by cooking pork, beef, and fish properly. Although most meats and fish are inspected under government supervision, eggs and larvae are not always detectable; the only certain protection is proper cooking.

Once it is inside the body, the tapeworm can be eliminated by specific anthelmintic drugs or surgery. The drug of choice is usually praziquantel, which should be given in a dose large enough to cause the worm to release its hold and pass out through the intestinal tract. If the head is found in the evacuated feces, no further treatment is necessary. However, if the head is not found, the worm could regenerate in two to three months, with segments reappearing in the stools.

Echinococcus granulosus and E. multilocularis differ from other tapeworms in that the adults infect animal hosts and the larval forms are found in humans. The larvae develop in the human intestine, penetrate its wall, and are carried by the lymphatics to various organs of the body where they form slowly growing cysts (hydatid cysts). The liver is the organ most commonly involved. Treatment is by surgical removal of the cyst. Infection with this worm (echinococcosis or hydatid disease) is uncommon in the United States.
Tapeworm: Life cycle of Taenia spp. From Mahon and Manuselis, 2000.
armed tapeworm Taenia solium.
beef tapeworm Taenia saginata.
broad tapeworm Diphyllobothrium latum.
dog tapeworm Dipylidium caninum.
fish tapeworm Diphyllobothrium latum.
hydatid tapeworm Echinococcus granulosus.
pork tapeworm Taenia solium.
unarmed tapeworm Taenia saginata.
A tapeworm that parasitises freshwater fish of temperate zones in the Northern hemisphere—D pacificum infestation occurs in marine fish off Peru
Definitive hosts Humans, domestic pets, other mammals
D latum is the largest known vertebrate tapeworm, measuring 10 meters in length with 4000 proglottids—most distal proglottids disintegrate, releasing eggs into the faeces; these mature and hatch into ciliated coracium, which are ingested by the first intermediate host, an aquatic arthropod, the copepod, and then ingested by a second intermediate host, a freshwater fish—e.g., salmon, trout, and whitefish; the eggs develop into procercoid larvae in the fish muscle and viscera and are eaten by man as raw fish and the cycle continues
Management Niclosamide

fish tapeworm

Diphyllobothrium latum A tapeworm that parasitizes freshwater fish of temperate zones in the Northern hemisphere Clinical Infection is usually limited to one worm, which causes CNS and GI symptoms, abdominal discomfort, weakness, loss of weight, malnutrition, and megaloblastic anemia Treatment Niclosamide

tapeworm

members of the genera Taenia, Diphyllobothrium, Dipylidium and Echinococcus; includes infestation with members of the tapeworm class Eucestoda. Most tapeworm infestations have little apparent effect on the health of farm livestock and are mostly esthetic problems in companion animals.

armed tapeworm
taeniasolium.
beef tapeworm
taeniasaginata.
broad tapeworm
dog tapeworm
dipylidiumcaninum.
fish tapeworm
hydatid tapeworm
echinococcusgranulosus.
pork tapeworm
taeniasolium.
unarmed tapeworm
taeniasaginata.
References in periodicals archive ?
Several recent publications report outbreaks of human cases of infection by the fish tapeworm Diphyllobothrium latum in Brazil (5-9).
The link that closes the epidemiologic chain between the Brazilian outbreak of fish tapeworm infections and the aquaculture of salmon in southern Chile is that some of the freshwater lakes where D.
The fish tapeworm life cycle is subsequently closed in these lakes when humans and animals, the definitive hosts of these fish tapeworms, ingest infested fish (11-16).
In Chile, infestation of humans with the fish tapeworm in the D.
Thus, to avoid new human outbreaks of fish tapeworm in other geographic areas where this parasite does not exist, salmon originated from aquaculture should not be eaten raw, at least not until it has been frozen under the conditions discussed above.