Tapeworms

Diphyllobothrium spp. Diphyllobothrium latum are broad fish tapeworms reported from humans.

Diphyllobothriasis is the name of the disease caused by broad fish tapeworm infections and is characterized by abdominal distention, flatulence, intermittent abdominal cramping, and diarrhea onset about 10 days after consumption of raw or insufficiently cooked fish.

The larva that infects people is frequently encountered in the viscera of freshwater and marine fishes. D. latum is sometimes encountered in the flesh of freshwater fish or fish that are anatropous (migrating from salt water to fresh water for breeding). Bears and humans are the final or definitive hosts for this parasite.

D. latum is a broad, long tapeworm, often growing to lengths between 1 and 2 meters (3-7 feet) and capable of attaining 10 meters (32 feet).

D. pacificum normally matures in seals or other marine mammals and reaches only about half the length of D. latum .

Treatment is the drug, niclosamide, which is available to physicians through the Centres for Disease Control's Parasitic Disease Drug Service.

Seeing eggs in feces on microscopic examination diagnose the disease.

 

Tapeworms in Gefilite Fish

Diphyllobothriasis is rare in the United States, but it was formerly common and known as "Jewish or Scandinavian housewife's disease" because the preparers of Gefilite fish or fish balls tended to taste these dishes before they were fully cooked.

Some persons are more genetically susceptible, usually persons of Scandinavian descent and develop a severe name. This anemia results from the tapeworm's stealing all the dietary Vitamin B12.

Foods are not routinely analysed for larvae of D. latum , but microscopic inspection of thin slices of fish, or digestion, can be used to detect this parasite in fish flesh.

 

 

Nanophyetus spp.

Nanophyetus salmincola or N. schikhobalowi are the North American and Russian troglotrematoid trematodes (or flukes). These are parasitic flatworms. Nanophyetiasis is the name of the human disease caused by these flukes.

Symptoms include increase of bowel movements or diarrhea weight loss and fatigue, abdominal discomfort and nausea

Diagnosis is done by detection eggs in stool.

Raw, under processed, and smoked salmon and steelhead are associated with cases.

 

Eustrongylides sp.

Larval Eustrongylides sp. are bright red roundworms (nemotodes), and occur in freshwater fish, brackish water fish and in marine fish.

When larvae are consumed in undercooked or raw fish, they attach to the digestive tract. Penetration into the gut wall is accompanied by severe pain as the nematodes perforate the gut wall. Removal of the nematodes by surgical resection or fiber optic devices with forceps is possible is needed

Those consuming whole minnows are at greatest risk. These large worms may be seen without magnification in the flesh of fish and are normally very active after death of the fish.

 

 

 

Ascaris lumbricoides and Trichuris trichiura

The eggs of these roundworms are "sticky" and may be transmitted to the mouth by hands, other body parts, fomites (inanimate objects), or foods.

Ascariasis and trichuriasis are the names of these infections. Ascariasis is also known commonly as the "large roundworm" infection and trichuriasis as "whip worm" infection.

 

Infection with one or a few Ascaris sp. may be asymptomatic unless noticed when passed in the feces, or, on occasion, crawling up into the throat and trying to exit through the mouth or nose. Infection from numerous worms may result in a pneumonitis during the migratory phase when larvae that have hatched from the small intestine penetrate into tissues and travel by way of lymph and blood to the lungs. In the lungs, the larvae break out and ascend into the throat and descend back down the small intestine where they grow.

Molting (ecdysis) occurs at various points along this path and, typically for roundworms, the male and female adults in the intestine are 5th-stage nematodes. Vague digestive tract discomfort accompanies the intestinal infection. Some worms wander and may locate in diverse sites throughout the body causing complications.

Treatment with anthelmintics is likely to cause the intestinal adult worms to wander.

Trichuris sp. larvae do not migrate after hatching but grow and mature in the intestine. Symptoms range from inapparent through vague digestive tract distress to emaciation with dry skin and diarrhea (usually mucoid). Toxic or allergic symptoms may also occur.

Both infections are diagnosed by finding the typical eggs in the patient's feces; on occasion the larval or adult worms are found in the feces or, especially for Ascaris sp., in the throat, mouth, or nose.

 

Worms are found in poorly treated sewage-fertilizer. Humans are infected when produce is consumed raw. Infected food handlers may contaminate a wide variety of foods.

 

Both infections may self-cure after the larvae have matured into adults or may require antihelmintic treatment. In severe cases, surgical removal may be necessary. Allergic symptoms (especially but not exclusively of the asthmatic sort) are common in long-lasting infections or upon reinfection in Ascariasis.