Stages of development of the bovine tapeworm. Stages of development of bovine tapeworm Pork and bovine tapeworm: similarities and differences

Scolex (head part) of a pork tapeworm under a microscope

Pork tapeworm (armed tapeworm or pork tapeworm) is a type of tapeworm that most often chooses a pig or wild boar as an intermediate host. The final host is exclusively human, but he can also act as an intermediate host.

The lifespan of an adult pork tapeworm in the body of the definitive host can reach up to 25 years.

Structure

The respiratory system does not require oxygen, i.e. anaerobic. Nervous – poorly developed. The reproductive system is highly developed - the worm produces a huge number of eggs (up to 5 million per day). Digestive system absent.

Life cycle

When consuming pork that has not undergone the required heat treatment, a person becomes infected. After the cysticercus enters the intestine, it turns its head outward and clings to the intestinal walls with the help of suction cups and hooks. Then new segments grow from the end and within about two months adult individuals are formed. The development cycle closes.

People can also accidentally become intermediate hosts, when they become infected with eggs with a developing embryo while consuming contaminated products.

Damage caused

The helminth enters the human body through food, unwashed hands, dishes, dirty laundry. The danger is that during vomiting the larvae may end up in the stomach. They get there from the intestines and are easily spread throughout the body.

Adult live pork tapeworm on glass

In many cases, cysticercosis leads to brain damage, blindness, tumor-like growths and decreased eosinophil levels. This causes serious neurological problems such as hydrocephalus, meningitis, and seizures, which often leads to death.

The main preventive measure is good heat treatment of pork. Meat can be frozen at -10°C for 5 days. Dirty hands are also the cause of human infection with cysticercosis. Therefore, maintaining personal hygiene is considered an effective preventive measure.

Bovine and pork tapeworm in humans: symptoms, treatment

• Bull tapeworm
• Sources of infection
• Symptoms
• Diagnostics
• Treatment
• Prevention
• Video

The uninvited “cohabitants” of our body include flat or tapeworms from the group of protostomes: bovine and pork tapeworms, broad tapeworm (tapeworm) and dwarf tapeworm. They are not only the largest, but also the most dangerous, and here's why:

Bull tapeworm

This type of helminth is called Taeniarhynchus saginatus or naked tapeworm. It differs in that at its head end the scolex has suction cups that allow it to be fixed to the intestinal wall. This worm looks like a thin ribbon consisting of 1000 or more segments (proglotids), reaching a length of adult 10-12 m.

This helminth is a direct relative of the bovine tapeworm and is called tenia solium ( Taenia Solium), but in contrast it is called armed, because on the head of the scolex, in addition to suckers, there is a corolla of chitinous hooks. This allows the worm to attach more firmly and penetrate into the thickness of the intestinal wall.

Neither artiodactyls nor pigs can get sick with either taeniarinhoz or taeniasis for the simple reason that they do not eat meat. But they eat food contaminated with worm eggs, which are excreted in human feces. This is the “continuity” between domestic animals and their owners, without which neither one nor the other can develop the disease.

Advice: a person can also become infected with tapeworm eggs from his own relative, and then he develops, like animals, cysticercosis. The larvae spread to all organs and tissues of the body, affecting them, as well as forming encapsulated fins.

Symptoms

Despite the fact that tapeworms are quite large, they can remain in the body undetected for a long time. The symptoms they cause are not specific and can be mistaken for other diseases. This:

• periodic abdominal cramps, bloating;
• bowel dysfunction - constipation, diarrhea;
• poor appetite;
• feeling of nausea;
• headache;
• increased fatigue, poor sleep;
• weight loss;
• pale skin caused by anemia;
• skin rashes, itching;
• thinning hair, thinning nail plates;
• decreased immunity, increased susceptibility to various infections.

In case of severe intoxication there may be significant changes hematopoiesis (blood formation), which can be mistaken for a hematological disease. Damage to the intestinal wall by scolex hooks causes the development of peritonitis. It shows up severe pain in the abdomen, plank-like tension in the abdominal muscles, increased body temperature. Sometimes yellowish-white fragments can be seen in the feces - separated segments of the worm up to 2 cm long.

Diagnostics

Many people believe that testing stool for worm eggs provides a 100% guarantee of their detection. This is not entirely true. Fecal analysis for helminths is mandatory, but it is not always possible to detect them, even after repeated studies. Just as testing feces for enterobiasis does not always reveal pinworms and their eggs.

The proglotids of a bovine tapeworm do not come out every day, but in a pork tapeworm they do not crawl out at all. Therefore, stool tests are taken multiple times. A blood test is also carried out, which reveals anemia, eosinophilia, and leukocytosis. An ultrasound of internal organs is prescribed.

The most informative is a modern serological blood test - the determination of specific antibodies against tapeworm.

Teniarinhoz is treated according to one of the following regimens:

1. Praziquantel is prescribed once at a rate of 15 mg of the drug per 1 kg of body weight.
2. Niclosamide – 2 g once for adults; children’s dose is selected individually. Before taking, drink 1 teaspoon 10-15 minutes before taking baking soda, diluted in half a glass of water.
3. Fenosal or dichlorsal for adults 2 g, dissolved in ½ glass of water, once at night, 2-3 hours after meals.

After ingestion, increased withdrawal of segments begins, which can last up to 2-3 months, sometimes a whole individual can come out. After the proglottide has stopped expelling, a re-examination is carried out.

Treatment for pork tapeworm is basically the same, but patients are often hospitalized for observation, because the eggs of this helminth, when their shell is destroyed, can easily turn into larvae right in the intestines and cause cysticercosis in the patient. After treatment, the patient is observed for a year every 3-4 months, with repeated examinations, and, if necessary, repeated administration of anthelmintic drugs.

Advice: Herbal remedies alone cannot get rid of tapeworm. Only special anthelmintic chemotherapy drugs can do this, and herbal remedies can be used as an addition to treatment.

Prevention

The set of measures to prevent taeniarinchiasis, taeniasis and cysticercosis includes both personal and systemic prevention.

Personal prevention:

• meat should be purchased only from places where sanitary control is carried out;
• carefully inspect the product to see if there are any yellowish-white inclusions or spots on it;
• avoid eating poorly processed meat, and even more so a raw food diet (raw liver, salted and pickled raw meat, rare steak, and so on);
• careful observance of personal hygiene.

Systemic prevention. These measures fall within the competence of the sanitary-epidemiological and veterinary services, they include:

• monitoring the condition of the sewerage system, wastewater treatment;
• veterinary supervision of livestock on farms;
• checking raw meat products entering the retail chain;
• sanitary and epidemiological supervision of meat industry enterprises.

Video

Teniarinhoz, or bovine tapeworm

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The structure of the bull tapeworm

Feces infected with bovine tapeworm oncospheres end up on the soil and hay. Helminth eggs are not afraid of moderate cold and can overwinter in the soil. But under the influence of ultraviolet radiation and a temperature of 30-37 degrees, oncospheres die.

The intermediate hosts of bovine tapeworm are cows, bulls, deer, and buffaloes. These animals, feeding on grass contaminated with helminth eggs, become carriers of the disease.

The larva of a bovine tapeworm through the walls of a cattle intestine is able to penetrate into the bloodstream, spread throughout the body and settle in the muscles and connective tissues. Here the larvae develop into a cysticercus within 4 months. These are the so-called bull tapeworm Finns. They can live in the body of livestock for about nine months, then die. In Fig. Figure 1 shows the development cycle of the bovine tapeworm.

The Finn enters the human intestine through contaminated, raw or poorly cooked meat. Here it is transformed, the head with suction cups is exposed and firmly fixed on the mucous membrane. Then the formation of an adult begins tapeworm.

The development of bovine tapeworm from cysticerci in the human body occurs within 80 days. After this, the sexually mature segments of the helminth break off and are excreted along with human feces. So life cycle the bull tapeworm closes and repeats again.

Main signs of helminth infection and its diagnosis

• the nervous system becomes upset, increased fatigue, weakness, headaches and insomnia appear;
• heartburn, nausea, vomiting, dyspepsia or constipation, abnormal salivation;
• non-localized pain in the abdominal area, without a specific location: in the stomach, on both sides of the abdomen or in its lower part;
• a sharp change in appetite from complete absence to severe hunger;
• The main and indisputable sign of infection with a bovine tapeworm is the exit of the worm segments through the anus alone or with feces.

Diagnosing bovine tapeworm infection is difficult, especially at the initial stage due to mild symptoms. To determine the diagnosis, the following is used:

If infection with this helminth could not be detected on early stage, then in a later period there may be complications of the disease in the form of intestinal obstruction, perforation of its walls and, as a consequence, the occurrence of peritonitis, pancreatitis, appendicitis, and disruption of the biliary system. The outcome of the disease is positive in most cases.

Treatment of the disease and prevention of infection with bovine tapeworm

After a quarter of an hour, take Fenasal, dissolved in 100 ml of sweetened water. The exact dosage is strictly as prescribed by the doctor, on average it is no more than 2-3 g for an adult patient.

Bovine tapeworm is also removed from humans using dry fern extract, pumpkin seeds and cleansing enemas, which are done in the evening before taking the herbal medicine and in the morning on the day of treatment.

To prevent the disease, you must avoid eating raw or undercooked meat. Roasting or boiling time for meat is at least an hour. For information: Finns can survive helminths inside large pieces of kebab weighing 50 g when fried. Therefore, it is better to buy meat that has passed veterinary control, or to boil it well.

Pork and bovine tapeworms: similarities and differences

This helminth looks like a microscopic head with a proboscis on which 6 chitinous hooks are located. A neck and body grow from the head in the form of a white ribbon. The length of an adult worm can reach from 1 to 6 meters.

Pork tapeworm is easier to remove than bovine tapeworm, but infection with it is many times more dangerous. Pork tapeworm larvae can grow in the human body, which is extremely dangerous for humans.

With the help of hooks, the larvae make their way through the intestinal walls into the circulatory system, spread throughout the body and settle in other organs: in the stomach, liver, even in the brain and eyes. Such cases of damage are irreversible, manifest themselves in the form of seizures, convulsions, loss of vision and end fatal for a sick person.

Such serious consequences of the disease should accustom people to the idea of ​​never consuming meat from livestock that has not passed the control of veterinary services, not eating questionable kebabs, and avoiding public toilets, always wash your hands with soap after visiting crowded places.

Strict adherence to the rules of nutrition and personal hygiene will completely protect a person from infection with dangerous helminths.

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Figure: development and structure of the bovine tapeworm

Features of the structure of the bovine tapeworm

Bovine tapeworm nutrition

Reproduction of the bovine tapeworm

Like most other flatworms, tapeworms are hermaphrodites. In each of its segments, except for the youngest, there is one ovary and many testes. The eggs mature only in the oldest, posterior segments. These segments break off and come out with feces.

Bovine tapeworm development

Large cattle can swallow tapeworm eggs along with the grass. In the stomach of the animal, microscopic larvae with hooks emerge from the eggs. With their help, the larvae burrow into the wall of the stomach, enter the bloodstream, spread throughout the animal’s body and penetrate the muscles. Here the six-hooked larva grows and turns into Finnish- a bottle the size of a pea, inside of which there is a tapeworm head with a neck.
In undercooked or undercooked meat, tapeworm larvae are kept alive. If a person eats such meat, he becomes infected with it. Bovine tapeworm secretes toxic substances, which cause intestinal disorders and anemia in humans.

Each segment (proglottid) of the bovine tapeworm includes male and female genital organs. The head (scolex) is located in the center in the photo

History of discovery

Morphology

Proglottids. The strobila consists of a chain of proglottids (segments), which are mainly filled with eggs. New proglottids are produced at the neck and this growth pushes the more mature segments towards the posterior end, where they break off and thus release thousands of eggs. This process is very important in the complex life cycle of this tapeworm. The bovine tapeworm is the largest human helminth of its kind, consisting of 1,000 to 2,000 segments, which can remain viable in the human intestine for up to 25 years.

Scolex. The scolex of the bovine tapeworm has a diameter of 1.5 - 2 mm and consists of four suckers at the anterior end flatworm, which are used as a means of attachment to the intestinal wall of the host. The bovine tapeworm lacks hooks on the scolex, unlike its close relative pork tapeworm, which infects domestic pigs and then humans. The eggs of both types of tapeworms are indistinguishable. They have a round or oval shape, covered on top with a thin (approximately 31-43 microns), colorless shell.

The egg contains the larval form (oncosphere) of T. saginata, surrounded by a double-edged yellowish-brown shell, which is destroyed after the eggs are released. The oncosphere has 6 hooks.

Life cycle

1. Mature, egg-filled segments (proglottids), located in the intestines of the final host (human), are excreted into environment along with feces. Each such segment contains up to 100 thousand eggs, which already contain infective larvae.
2. These proglottids are able to move through the grass and soil for some time, spreading eggs, which are then absorbed by large horned cattle (cattle) along with contaminated vegetation and enter the gastrointestinal tract of their intermediate host.
3. Enzymes and intestinal acids destroy the egg shell and release oncospheres (larvae), which, damaging the intestinal epithelium, can be transported through the bloodstream throughout the body of the cattle. After this, the larvae penetrate the muscle tissue, the oncosphere fills with liquid and turns into a fin (cysticercus).
4. To complete complex cycle development, raw or poorly cooked beef must be eaten by a person (the definitive host) and then enter the human digestive system. Digestive enzymes destroy the cysticerci, the larval cysts are released, and their inverted scolex is able to come out and attach to the walls of the host’s intestine.
5. Next, the maturation of adult individuals occurs, during which the head and neck begin to grow rapidly, producing more and more new proglottids. The bull tapeworm increases in size, and within three months it can reach a length of up to 5 meters. After maturation, mature egg-containing proglottids separate from the tapeworm, and the life cycle restarts.

Routes of infection

Bovine tapeworms enter the human body by consuming raw or undercooked beef. On average, 2-3 months pass from the moment of infection to the formation of a sexually mature individual. Helminths can maintain their vital activity in the body of the definitive host for up to 25 years.

Cases of the disease are more common in adults than in children, which is explained by dietary habits. It is also noted that people working in meat processing plants, slaughterhouses or in various food establishments (cooks) suffer from teniarinhoz more often than others.

Geographical distribution

Signs and symptoms

Most people infected with bovine tapeworm do not experience any symptoms unless the tapeworm grows quite large. In such situations, a person may experience a feeling of fullness, and sometimes (rarely) even nausea to the point of vomiting. Worm or worms in in rare cases can cause acute intestinal obstruction, and individual proglottids can block the vermiform lumen, causing acute appendicitis.

In addition, with teniarynchosis the following may be observed:

• loss of appetite;
• weight loss;
• headache;
• general weakness;
• itching in the anus.

Often patients become aware of the infection by finding a proglottid (or large segment of the worm) in the stool during bowel movements. These proglottids sometimes crawl down the thighs, usually when a person is active, and produce a tickling sensation.

The presence of infection may also indicate elevated levels eosinophils and immunoglobulin E (IgE).

It should be noted that a significant difference between porcine and bovine tapeworms is that the cysticercus stage does not occur in humans with T. saginata when eggs are ingested. Therefore, infection with a bovine tapeworm is less dangerous than with a pork one, since in the latter case cysticerci can enter the central nervous system, eyes and other organs, developing into small subcutaneous cysts. Then they talk about cysticercosis.

Treatment and prevention

As with most cestodes, treatment involves the use of. Niclosamide is also effective in this situation.

Among folk ways To get rid of worms, the most popular are pumpkin seeds and garlic-milk mixture.

In the human intestine, and its larvae develop in body cattle.

External structure

Height

The growth of the worm and the increase in the number of segments continues throughout its life. New segments are formed in the cervical area. At first they are very small, but towards the posterior end of the body they increase. The posterior segments are periodically torn off.

Cover

The cover of the bovine tapeworm is epithelium with a cuticle; longitudinal and circular muscles are attached to them, together forming a skin-muscle sac.

Digestive system

Reproduction and life cycle

Reproduction at the bull tapeworm sexual. Fertilization or between segments, or self-fertilization. In each of the median segments there are two ovaries, many testes and a uterus in which fertilized eggs develop, coming out with the last segment of the tapeworm along with feces.

Cattle can ingest tapeworm eggs in grass. In the stomach of the animal, microscopic larvae with hooks emerge from the eggs. With their help, the larvae drill into the wall of the stomach, enter the blood, spread throughout the animal’s body and penetrate the muscles. Here the larva turns into a finna - a pea-sized bladder, inside which the tapeworm head with a neck is hidden.

In undercooked or undercooked meat, tapeworm larvae are kept alive. If a person eats such meat, he becomes infected with it. Bovine tapeworm secretes toxic substances, which cause intestinal disorders and anemia in humans.

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