Wide Ribbon: Symptoms and Prevention

The largest helminth that can parasitize in humans and animals is the wide ribbon (Diphyllobothrium latum or Dibothriocephalus latus): its adult individual can grow up to 12 meters in length.

Biological systematics of a wide tapeworm classifies it as a type of flatworm, a class of tapeworms (cestodes), a group of pseudophyllides - lentets.

This parasite can be considered a long-liver, because sometimes he lives for two or three decades.

The structure and life cycle of a wide ribbon

The structure of a wide ribbon is typical for cestodes, whose body (strobila) looks like a flat ribbon consisting of segments. However, in the wide ribbon, the transverse size of the mature segments of the strobila is up to 10-15 mm, and their length, as a rule, does not exceed 3 mm.

The head or scolex of a wide ribbon has the shape of a very elongated oval about 3-4 mm in length and is provided with a pair of botryls - slit-like depressions, through which the worm attaches to the wall of the intestine of the host (human, cat, dog, etc.).

Behind the scolex is the cervix - the growth zone, where all the time new segments of a wide ribbon (proglottids) are formed, and the width of the segments increases as you move from the cervix to the posterior part of the body. One ribbon can have up to three thousand segments.

Each segment is covered with a dense cuticle, which has microstriae - villous outgrowths, with which the cestode densely attaches itself to the microvilli of the intestinal mucosa and thus feeds by pinocytosis - sucking out the substances needed by the whole body. A wide ribbon does not need oxygen, so it lacks a system of respiration and circulation. And he selects the waste of his vital activity protonefridialnym way - through the system of tubules. And every proglottis has such a system.

And each segment has an autonomous hermaphrodite reproductive system with a complete set of transforming reproductive organs. As a result of its functioning, the uterus (in the form of a socket with a hole) is formed inside the joint, containing eggs of a wide ribbon, ellipsoidal or oval in shape, 40-65 microns in size. At one end of the egg there is a lid, and inside it ripens a spherical larva - coracidium (or oncosphere) with a sheath and hooks. This is the first larval stage of the worm.

The definitive or definitive master of a wide ribbon is a person, as well as predators eating fish, in the small intestine of which the helminths develop to the mature state and begin to multiply.

The life cycle of a wide ribbon lasts about six months and begins with the moment when mature proglottids release eggs and, in the end, break away from scolex. From the large intestine, eggs (along with feces) fall outside.

Coracidium leaves the shell only when the egg is in the aquatic environment (at + 15-18 ° C), where it ripens within 1-2 weeks and opens the lid. Movable coracidia float in the water and serve as food for the Cyclops, which inhabit the water bodies. And this is the first intermediate owner of a broad ribbon. In the organism of the cyclopa, the coracidium penetrates through all the tissues through the intestine, and within 15-20 days a Finn of a wide ribbon is formed - a worm-like procercoid of dimensions not exceeding 0.5 mm.

The second intermediate host of a wide ribbon, which parasitologists call an auxiliary, is the fish that eats the Cyclops. Having penetrated from the stomach into all the organs and muscle fibers of fish, the procercoids grow for a while, and then go on to the next stage - the plerocercoid of a wide ribbon (sparganum), which is a white oblong larva 10-25 mm in size with a recessed inner scolex. This stage of the parasite is invasive.

Most parasitologists recognize the presence of a broad tapeworm third intermediate host, because people usually do not eat small raw fish. Therefore, if the predatory fish - perch, pike, pike perch, trout or salmon - caught and ate small fish with plerocercoids, then the larvae again enter the intestine and migrate to the flesh of the large fish.

Ways of infection with a wide ribbon - oral, through eating poorly cooked or roasted fish, infected with the faces of the parasite - not only freshwater, but also some marine species. You can get infected after eating caviar of weak salting, lightly salted or raw fish. In particular, Canadian doctors warn of the potential threat of invasion by a wide ribbon with the use of such popular dishes from raw fish, as carpaccio, tartar and seviche.

It is not necessary to exclude the possibility of infection through the ingestion of fecal particles of infected parasite hosts (humans and animals), as well as untreated wastewater, to other food.

The incubation period - from the moment the larva-plerocercoid enters the body before the onset of symptoms of infection - lasts from one to three months.

Symptoms of a wide tapeworm

As noted by infectious disease doctors, the symptoms of a wide tapeworm quite often may not have a pronounced clinic. Typical gastrointestinal symptoms of infection with a wide ribbon - diphyllobothriasis - are manifested by nausea, epigastric pains, alternating diarrhea and constipation, changes in appetite, loss of body weight. Possible headaches and general weakness.

In some cases there is an obstruction of the intestine, limbs become numb, convulsions occur, soreness and burning of the tongue are felt (especially after salty and sour food).

Also for diphyllobothriasis is the development of the so-called pernicious anemia associated with the presence in the small intestine of a wide ribbon of considerable dimensions. This, on the one hand, reduces the absorption of cyanocobalamin (vitamin B12), coming from food, and, on the other hand, damage by the parasite of intestinal walls disrupts the production of this vitamin by intestinal bacteria. In addition, as it turned out, this vitamin is absorbed by the parasite itself.

Since B12 provides many processes in our body, including the exchange of nutrients and the formation of red blood cells, its deficiency can lead to permanent weakness and dizziness, pallor of the skin and a decrease in its tactile sensitivity, swelling of soft tissues and rapid pulse, deterioration of blood coagulability, redness and fissures on the mucous membrane of the tongue (glossitis), loss of taste and difficulty swallowing. There may be seizures similar to epileptic ones.

On the part of the blood, it is possible to accelerate the ROE and increase the bilirubin content. In this case, the number of erythrocytes and hemoglobin in the blood can be normal, but macromegalocytosis is noted - an increase in the size of red blood cells.

In addition, allergies to the products of helminth vital activity may develop, which is expressed in the eosinophilia of blood-an increase in the level of leukocytes-eosinophils, which are produced by the bone marrow to protect the body from foreign proteins.

Diagnosis and treatment of a wide tapeworm

Diagnosis of a wide tape includes: examination of the patient and collection of anamnesis; general stool analysis (coprogram); clinical blood test. It may be necessary to analyze gastric juice for gastromucoprotein.

Treatment of a wide tapeworm is carried out by ingesting such drugs as Fenasal or Biltricide.

In case of diphyllobothriasis, the daily dose of anthelminthic drug Fenasal in tablets of 0.25 g (other trade names of the drug - Nichlosamide, Yomezan, Biomezan, Cestozid, Helmiantin, Linteks, etc.) is taken at one time (in the morning on an empty stomach or 4 hours after dinner , at night); Before taking the drug, you should drink half a teaspoon of baking soda. The standard dose for adults and children over 12 years is 8-12 tablets, for children 5-12 years - 6 tablets, 2-5 years - 4 tablets, up to 2 years - 2 tablets. Tablets must be crushed into powder or simply chewed well. You can take food 3-4 hours after taking the tablets, the food should be light and best in liquid or semi-liquid form. A month after the treatment, it is necessary to pass an analysis of feces for the presence of eggs or larvae of the tape. Fenasal is contraindicated in anemia, stomach ulcer and pregnancy.

Treatment with Biltricidum (other trade names - Praziquantel, Biltrid, Cesol, Cestoks, Cystricidum, Azinox) is effective due to the paralyzing effect of praziquantel on the helminth organism, leading to its death. The drug is produced in tablets of 0.6 g and is administered by mouth at 0.04 g per kilogram of body weight - once a day (while eating, squeezed with water).

Taking Biltricida can cause discomfort in the abdomen, nausea, vomiting, diarrhea (with a trace of blood), dizziness and headache, fever, increased drowsiness, hives, seizures. The active substance of this drug has a destructive effect on the pancreas and liver cells, can lead to the development of toxicological hepatitis and cirrhosis of the liver. It is not used in the treatment of children under 4 years old and pregnant.

Often treatment of a wide ribbon at home is carried out with raw pumpkin seeds, which are advised to peel, grind and eat on an empty stomach. Adults need to eat 200-300 grams of seeds prepared in this way for the day, children up to 100 grams. But before that you should also prepare your bowel: two days before receiving the "dose" of seeds, you need to clear it with enema for the night, and the next day take saline laxative.

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Prevention of a wide ribbon

Since a person can not destroy this parasite in nature (especially considering the discharge volumes and the quality of wastewater treatment), the only possible prevention of a wide ribbon is to cook fish properly. First and foremost, it is its thermal and thermal treatment sufficient for the duration and temperature level: temperatures + 60 ° C and above, the plerocercoids do not survive, and after 20-25 minutes they die. Also, you must correctly salt fish (with a salt concentration of 10%) and freeze (at -15-10 ° C).

According to WHO estimates, a wide ribbon parasitizes in the intestines of almost 15 million people worldwide, especially among those in countries where many fish are consumed.