Pig manganese: characteristic, symptoms, treatment and prevention

According to the classification of zoonotic parasites, porcine tapeworm or porcine tapeworm (Taenia solium) is the cestode (cestoda) of the cyclophyllide (cyclophyllidea) order of the Taeniidae family. This widespread intestinal worm is especially common where people eat pork.

The diseases caused by this parasite are called teniosis and cysticercosis, refer to helminthiasis and have a code for ICD-10 - B68.0 and B69.

[1],

Structure of pork chain

Like all flat worms of parasitic family, the structure of the pork chain consists of a triploblastic acoelomate body - a ribbon of white color that does not have a coil (filled with a liquid of cavity) up to two or three meters in length.

The elongated flat body of the pork chain or strobila consists of a chain of segments (segments) - proglottids, the number of which ranges from 150-200 to 800-900. Each segment of the pork chain is a full reproductive part.

At the anterior end of the worm there is a 1 mm scolex, which connects to the strobila through a short neck. The scolex of the pork chain has an organ attached to the wall of the intestine of the host: four radially arranged round suckers, surrounded by a rostellum (spout), provided with 22-32 chitinous hooks.

The entire body of the pork chain is covered with tegument, and its structure in these cestodes is unique. Since - for lack of internal cavities - the digestive organs and excretion of these worms, the digestive system of the pork chain, as well as the excretory system of the pork tapeworm are outward: the tegument is covered with an absorbent layer of microtriches. Each such microvilli has a plasma membrane covered with a glycocalysis consisting of proteoglycans (having a negative charge of polysaccharides).

Microvilli are the metabolically active organ of the pork chain, which simultaneously performs sensory, absorption, secretory and excretory functions. In addition, glycocalyx is responsible for inhibiting the digestive enzymes of the host and absorbing cations and bile salts. And the nutrients absorbed by the microvilli of the tegument penetrate the tissues of the chain by diffusion.

Habitat of pork chain

The habitat of the pork chain varies depending on the stage of its life cycle. At the egg stage, he lives in the feces of an animal; Oncospheres (larvae with embryo) live in the intermediate host - in the muscle tissues and the brain of the pig, which ate the debris with the feces particles. And the adult tapeworm lives in the intestine of the final host (person).

Ways of infection with pork chain are fecal-oral. Solitary invasion occurs when a person consumes pork infested with larvae; Also, the source of contamination is dirty raw vegetables and water, in which there may be detached segments of a pork chain with an egg-filled uterus or just eggs (which are able to survive outside the host for almost two months).

According to epidemiological data, the completion of the life cycle of this parasite occurs in those regions where people live in close contact with pigs and eat their insufficiently thermally processed meat. High prevalence rates are observed in Latin America, West Africa and sub-Saharan Africa, Eastern Europe, India, Pakistan and South-East Asia. In countries where the use of pork is forbidden by Islam, tenidosis and cysticercosis are extremely rare.

Life Cycle and Reproduction and Pork Chain

From the foregoing it is clear that the intermediate host in the development cycle of pork chop is one, and this is usually a pig (can also be a dog and a man). A person acts as the sole ultimate owner of a pork chain.

The life cycle of the pork chain includes several stages.

• Eggs of pork tapeworm or morula, in which the larvae-embryos (oncospheres) are, enter the intestine of a person through the mouth and then through the digestive tract. When the eggs with embryos enter the intestine, out of them, movable oncospheres come out through the "hatch".
• The noninvasive larva of the pork chain - oncosphere - after emergence from the egg by hooks is attached to the intestinal wall and then penetrates through the intestinal mucosa into the blood and lymphatic vessels, migrate to the striated muscles, brain and other tissues, where they settle to form the next larval stage - cysticerci.
• Cysticerca of pork tapeworm or fin of pork tapeworm is an invasive larva that forms from the oncosphere for about 70 days and can continue to grow throughout the year. At this stage, the larva has the appearance of a translucent, cloudy white oval vial containing a liquid and one invaginated protocalex. Under the influence of bile and intestinal digestive enzymes of the host, the scolex protrudes outward, and thus the Finn of the pork chain is attached to the intestinal wall and begins to grow in size, using nutrients entering the small intestine of the host. Getting into muscles and parenchyma of organs, the larva forms a cyst - a protective cuticular shell.
• An adult worm, formed from cysticerci for about 10-12 weeks after infection, lives in the human intestine. The strobila is lengthened, and in the region of the neck - the worm growth zone - new proglottids are formed. So the most mature and old proglottids are at the posterior end of the body.

This parasite belongs to the hermaphrodites, and the mature proglottid (segment of the pork chain) has a complete bisexual reproductive set. Reproduction of pork chain is provided by numerous testes and trilobate ovary, which are open to the general genital pores. The uterus of the pork tapeworm has 5-8 branches, but it is closed, that is, the eggs get out when the proglottid is rejected from the cestode body.

One proglottid can contain more than 50 thousand eggs with embryos. Mature proglottids with pregnant uterus are often ruptured in the intestines, releasing eggs falling into the stool, and with feces they go unhindered into the environment.

Symptoms of pig pincers

The affected organs of man with a pork chain are the small intestine, subcutaneous tissues, muscles, eyes, the brain and spinal cord.

The invasion of the human small intestine by adult worms of pork chopsticks causes a thin dose, which can be asymptomatic. However, the symptoms of pigmentation in severe forms of infection are manifested by weight loss, loss or increased appetite, anemia, abdominal pain, dyspepsia, nausea, constipation and diarrhea.

Infection with eggs of the pork chain (from which the larvae emerge) or proglottids that break in the intestine and can cause the migration of larvae into human tissues with the formation of cysts (Cysticercus cellulosae), leads to the development of a systemic infection with clinical symptoms, depending on the number, size and location of cysts . Very often, the symptoms of pigmentation in the larval stage may not occur for a long time. And when they manifest, doctors diagnose cysticercosis: cysticerci of the pork chain, penetrating under the skin on the trunk and extremities, form subcutaneous cysts in the form of firm, mobile and often painful nodules.

The Finn of the pork chain can be found in any muscle tissue of a person, causing muscle inflammation (myositis) - with fever, eosinophilia and false muscle hypertrophy, which initiates muscle swelling with the threat of their atrophy and fibrosis. In most cases, this form of invasion passes without obvious signs, since cysticerci die and calcify.

With diagnosed neurocysticercosis, cysticerciform cysts (from 5-20 mm to 6-8 cm in diameter) are localized in the parenchyma or subarachnoid space of the brain. They can be numerous and dangerous for life. Symptoms of pigmentation in cases of neurocysticercosis: headaches, dizziness, convulsions. The consequence of damage to the structures of the brain can be a violation of their functions (sensory and motor), which causes epileptic seizures and such neurological pathologies as a decrease in cognitive abilities, hydrocephalus, meningeal syndrome, mental disorders.

If cysts are formed in the ventricles of the brain, the outflow of cerebrospinal fluid is blocked and signs of increased intracranial pressure appear: migraine headaches, nausea, sudden changes in blood pressure, sleep disorders, periodic hyperhidrosis, lethargy, fatigue, decreased acuity of hearing and vision. When the spinal cord is affected, chronic back pain occurs.

Cysticerci can be found in the tissues of the eyeball and under the conjunctiva, which provokes retinal edema, hemorrhage, decreased vision or even loss of vision.

Diagnostics

To date, the diagnosis of human defeat with a pig chain includes:

• analysis of feces for eggs and proglottidas of the worm (can only reveal tsenia doses);
• blood test for antibodies to pork chain (study of serum with EITB-solid-phase immunoblotting);
• IF-analysis of cerebrospinal fluid;
• X-ray or ultrasound of the intestine;
• X-ray of subcutaneous and muscular tissues (for identification of calcified larvae-cysticercas and confirmation of cysticercosis);
• Computed tomography (CT) or magnetic resonance imaging (MRI) of the brain with suspected neurocysticercosis;
• examination of the fundus and conjunctiva (with ophthalmologic cysticercosis).

[2], [3], [4], [5]

Differences between pig and bovine chains

The pork chain has relatives - cestode Taenia saginata (bovine tapeworm) and is distributed in Asian countries Taenia asiatica (Asian tsepen).

As noted by parasitologists, there are differences between pig and bovine chains. First and foremost, they consist in the fact that the intermediate owner of a bull tattle is cattle; Bovine tapeworm is much larger (4-10 m in length), the uterus of the proglottid is more branched than in T. Solium, the ovary is bilobate, and the scolex does not have a rostella with hooks: instead of them, the worm T. Saginata only suckers.

In addition, bovine tapeworm has an interval of existence outside the hosts - in the environment (up to several weeks). When mature proglottids break away from the worm and fall into the feces, they can crawl to a more appropriate place - in the grass that grazes grazing livestock.

And the main difference: bovine tapeworm causes only helminthiasis of the type of dzenia, but does not cause cysticercosis and the most dangerous neurocysticercosis.

Differential diagnosis of infection with bovine and porcine chain is carried out by means of PCR analysis of blood serum.

As experts note, it is also important to differentiate neurocysticercosis from other pathologies of the brain (tuberculosis, tumors, etc.).

[6], [7], [8]

Treatment of Pork Chain

Prazikvantel (other trade names - Azinox, Biltrid, Biltricide, Zestocs, Cystricide), Nichlosamide (Fenasal, Cestocid, Helmiantine) and Albendazole (Aldazol, Sanoxal, Wormil, Nemozol) are antihelminthic agents used to treat the pork snack in particular, the dosis. To a lesser extent - cysticercosis, as when calcification of larval cysts, their involution occurs, and antiparasitic therapy does not bring any benefit.

Praziquantel is taken once from the calculation of 10 mg per kilogram of body weight. The drug is not used to treat children younger than 4 years and pregnant. Among the side effects, most often nausea, vomiting, abdominal pain, diarrhea with blood, dizziness.

Preparation Nichlosamide for adults and children with 12 years of age appoint 8-12 tablets (0.25 g each); children 6-12 years old - 6 tablets each; take an hour before meals or two hours after a meal; tablets are chewed (or ground into powder) and washed down with water. The duration of treatment can be up to seven days.

The tablet Albendazole (400 mg) is taken whole (after meals) once; children dose is calculated at 6 mg per kilogram of their weight. With cysticercosis of the brain take 800 mg of albendazole per day for 8-30 days. There may be side effects of the drug in the form of dyspepsia, abdominal pain, increased blood pressure, dizziness, changes in the level of leukocytes and platelets in the blood.

Prevention

Prevention of infection with pork chain includes both the observance of personal hygiene and careful heat treatment of pork (the meat must be well boiled and roasted). Also important is the level of sanitary supervision over the content of pigs and the quality of meat that goes on sale (especially in markets).

Forecast

The prognosis in many respects depends on the form and localization of pathology, which develops due to this helminthiasis. According to WHO, almost 400 thousand people in Latin America have some symptoms of dosis and cysticercosis; In Mexico, about 3.9% of the population has these diseases; in Guatemala, Bolivia and Peru - up to 20% (in pigs - up to 37%).

The level of infection of people with pigs in countries such as Ethiopia and Kenya is almost 10% of the population, and in Madagascar - 16%.

According to the global data for 2010, neurocysticercosis was the cause of death in 1200 cases. In the USA, for 12 years (from 1990 to 2002) 221 people died from cysticercosis; 62% of them were emigrants from Mexico, and, in all likelihood, pork tapeworm was picked up at home.