The Source Of Human Infection With Trichinosis, Which May Be

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The Source Of Human Infection With Trichinosis, Which May Be
The Source Of Human Infection With Trichinosis, Which May Be

Video: The Source Of Human Infection With Trichinosis, Which May Be

Отличия серверных жестких дисков от десктопных
Video: Trichinosis (Trichinellosis) Worm Infection 2023, February

Page content

  • The causative agent of trichinosis
  • How can you get infected
  • Development cycle
  • Trichinosis prevalence
  • Symptoms

    • Erased form
    • Light form
    • Trichinosis of moderate severity
    • Severe form
  • Symptoms in children
  • Trichinosis during pregnancy
  • Diagnostics of the trichinosis
  • Trichinosis treatment

    • Medication for trichinosis (drugs)
    • Surgical intervention for trichinosis
  • The mechanism of infection with trichinosis in animals

    • Infection symptoms
    • Prevention of trichinosis in animals
  • You can defeat parasites!

Trichinosis in humans is rightfully considered one of the most dangerous helminthiases, since it is impossible to get rid of the parasites that have entered the body completely, they remain in the muscles and remain active for up to 40 years.

This helminthiasis often leads to disability, and the death rate when infected with Trichinella reaches 30%. The transferred disease forms lifelong immunity (antibodies circulating in the blood protect against re-infection), but the immunity remains non-sterile (there are encapsulated larvae in the body).

What to do in such a situation? To get started, we recommend reading this article. This article details the methods of dealing with parasites. We also recommend contacting a specialist. Read the article >>>

The causative agent of trichinosis

The causative agent of this helminthiasis is Trichinella, the genus of which includes more than 10 species (class of nematodes) But only one of them causes this disease - the parasite Trichinella spiralis. Sexually mature individuals enter the digestive tract, where (small intestine) begin to actively reproduce. Trichinella are viviparous parasites, one female for the entire period of existence is capable of producing up to 2000 larvae.

Females do not exceed 1.8 mm in length, and after fertilization they reach 4.4 mm. In males, the body length is slightly less - 1.2 - 2 mm. It is characteristic that after fertilization, the male parasites die, and the females begin to excrete larvae. For Trichinella, humans are both the final (adults parasitize in the intestines) and intermediate (the larvae are in the muscles) host.


How can you get infected

What can be the source of human infection with trichinosis? The mechanism of infection with trichinosis is alimentary, and the route of transmission is oral, through meat infected with trichinosis. The disease belongs to natural focal, although the foci of infection can be not only natural, but also synanthropic.

In natural foci, helminthiasis is common among wild animals (a source of trichinosis):

  • wild boars;
  • bears (both brown and white);
  • foxes;
  • seals;
  • seals;
  • nutria;
  • badgers;
  • whales.

Synanthropic foci are formed in human habitats, after feeding game waste to domestic animals. Helminthiasis is common among pigs, dogs and cats. In this case, human infection with trichinosis occurs by eating infected pigs (in some areas of dogs).

Human susceptibility to this disease is quite high. When eating 10-15 grams of contaminated meat, parasite infestation occurs in 100% of cases. Characterized by the development of helminthiasis in whole groups of people or families after a joint feast and eating game.

How can you get infected
How can you get infected

Development cycle

In 1 - 1.5 hours after eating meat infected by the parasite larvae, they are released from the capsule in the digestive tract with the help of enzymes and gastric juice and penetrate into the small intestine. In 1.5 days, the larvae reach the stage of sexually mature individuals and on days 3-4, the female parasites begin to produce new larvae. The female can survive in the small intestine for 42 - 56 days. New larvae bore through the mucous membrane of the small intestine, penetrate into the lymphatic system, and from it into the circulatory system.

With the blood flow, the newly formed larvae are spread throughout the body and settle in the striated muscles (5 - 8 days after infection). As a rule, the muscles of all organs are affected, with the exception of the heart (muscles of the tongue and forearm, diaphragm and intercostal, gastrocnemius and deltoid). On days 17 - 18 after penetration into the muscles, the larvae mature and become infectious.

While the larvae are in the muscles, they actively begin to produce hyaluronidase, with the help of which they penetrate the muscle fiber where they are covered with a capsule (3-4 weeks). The capsule covering the larva provides nourishment and protection for it. After six months - a year, the capsule calcifies (calcium salts are deposited), which indicates the end of the development of the parasite.

Trichinosis prevalence

Natural foci of helminthiasis have been recorded in North America, Germany and Poland, in Ukraine and Belarus, as well as in the Baltic States. In the Russian Federation, trichinosis is most common in the Khabarovsk and Krasnoyarsk Territories, in the Magadan Region and in the Krasnodar Territory. In total, the disease is recorded everywhere, with the exception of the Australian continent.

Contribute to the spread of helminthiasis:

  • the ability of the pathogen to tolerate high and low temperatures, which ensures its survival in any climatic conditions;
  • high susceptibility of a person to trichinosis;
  • group outbreaks - collective consumption of contaminated meat;
  • unstable immunity, which provokes repeated infections after primary infection.


Treatment of the disease sometimes begins with a delay, since at a low intensity of invasion, an asymptomatic course can be observed, and the only sign indicating infection, in this case, becomes an eosinophilic blood reaction. Trichinosis can occur in different forms, depending on the severity of the course, the duration of the fever and the incubation period, as well as depending on the outcome of the disease.

Common clinical manifestations, as already mentioned, are facial edema, muscle pain, fever, usually of a remitting type, high eosinophilia, and skin rashes. But the symptoms will differ depending on the form of the invasion. There are four of them: worn out, light, medium and heavy. The course of invasion also includes four periods: incubation, acute manifestations, complications, convalescence, and relapses.

Swelling of the face upon infection
Swelling of the face upon infection

Swelling of the face upon infection

Erased form

The incubation period is 4-5 weeks. With this form, it is very difficult to diagnose trichinosis. Symptoms in humans are practically absent and are manifested only by malaise, low-grade fever, mild muscle pains, and pasty face. The disease lasts no more than a week, during this time all signs disappear.

Light form

The incubation period, as in the erased form, lasts 4-5 weeks. In this case, trichinosis begins with a sharp increase in temperature to 38-39 degrees and a headache. Symptoms (see photo below) are complemented by swelling of the eyelids and puffiness of the face. Also, this form is characterized by pain in the lumbar and calf muscles. All manifestations can go away on their own within one to two weeks.

Trichinosis of moderate severity

With this form, the incubation period lasts 2-3 weeks. The symptomatology in this case is more pronounced, corresponds to the allergic phase. The disease begins acutely, with a rise in temperature to 39-40 degrees. At such a high level, it remains for a couple of hours, and then drops to 38-38.5 degrees and stays that way for the entire first week. The second week is characterized by low-grade fever.

Fever is complemented by severe pain in the lumbar, occipital, calf, and chewing muscles. In some patients with hemorrhagic skin rashes, trichinosis is accompanied. Symptoms with this form are very pronounced, severe swelling on the face is observed. Some patients develop bronchopulmonary pathology, manifested by bronchitis, pleurisy, pneumonia.

During a fever, signs of damage to the heart and vascular system intensify: systolic murmur, tachycardia, deafness of heart sounds. With the help of an ECG, dystrophic disorders can be detected. Patients complain of shortness of breath, rapid heartbeat.

The involvement of the reticuloendothelial system in the pathological process is confirmed by an increase in the spleen and lymph nodes.

Swollen lymph nodes
Swollen lymph nodes

Swollen lymph nodes

In this form, the clinical manifestations of the disease reach their maximum at the end of the first week. Trichinosis can be completely cured in three to four weeks. Symptoms (treatment with folk remedies in this case is ineffective) in the form of muscle pains can persist for another 1-2 months.

Severe form

The incubation period is only 7-10 days, and in especially severe cases it can be reduced to 3-1 days. In this case, trichinosis often begins to manifest itself atypically. Symptoms occur the same as with flu or acute respiratory infections, typhoid or cheese fever, food poisoning.

From the first days, signs of damage to the central nervous system and general intoxication are pronounced. The temperature gradually rises to 40-41 degrees and remains at this level for two to three weeks. The fever is accompanied by severe headaches, insomnia, delirium, increasing muscle pain, severe edema.

The pain occurs in the chewing, gastrocnemius, and eye muscles, and then spreads to the muscles of the shoulder girdle and lower back. Often they are accompanied by contracture and limitation of mobility up to complete immobilization of a person.

Edema covers the trunk, limbs, brain membranes, tissue of internal organs, which leads to exophthalmos, functional disorders of the central nervous system, diplopia and other manifestations. A polymorphic rash appears on the skin.

Polymorphic rash
Polymorphic rash

Polymorphic rash

Pathology of the heart and blood vessels often develops with hypotension, cardiac arrhythmias and tachycardia. There are signs of heart failure, muffling of heart sounds is recorded. In almost all patients, ECG shows coronary abnormalities and diffuse changes in the myocardium.

The respiratory organs also suffer: there are focal bronchopneumonia, bronchitis with an asthmatic component. Abdominal syndrome is possible, manifested by loose stools with impurities of blood and mucus, abdominal pain, vomiting and nausea.

In this form of the disease, systemic and organ damage can lead to death. The cause of death, as a rule, is intestinal and stomach necrosis with bleeding and perforation, acute allergic myocarditis, pneumonia, accompanied by pleurisy and astmoid bronchitis, damage to the central nervous system.

Symptoms in children

As a rule, the incubation period in children is longer. Fever is less pronounced, short (up to two weeks) is more common than long-term remitting. The main symptoms that cause trichinosis are also less pronounced.

It is believed that such a mild course of the disease in children is due to the high immunological activity of the body and, as a consequence, the weak development of immunopathological manifestations. However, the possibility of a severe course of invasion with the occurrence of meningoencephalitis and allergic myocarditis cannot be ruled out. Even an unfavorable outcome is possible.

Trichinosis during pregnancy

There are clinical observations that suggest an easier course of this helminthiasis during pregnancy. In women expecting a baby, muscle pain, fever, and edema are less pronounced. Complications are also less severe and less common. Available studies indicate that trichinosis does not adversely affect the course of pregnancy and does not affect the development of the fetus.

Diagnostics of the trichinosis

Symptoms similar to other muscle pathologies indicate that this makes it difficult for specialists to make a diagnosis.

Trichinosis is diagnosed using laboratory tests. A fecal analysis is taken from the patient in order to identify the presence of the main pathogen - Trichinella. In addition, the following diagnostic measures are carried out:

  • General blood analysis. Trichinosis provokes in a person the appearance of too high levels of eosinophils in the blood. The content is 80% of the total number of leukocytes;
  • Serological diagnostics. Study of the reaction of erythrocytes to the addition of antigens taken from parasites.

This diagnostic method is divided into five types:

  • Complement fixation reaction (CBC). When antibodies are found in the patient's blood, they are grouped with the antigen and bind to the complement (an element involved in immune reflexes);
  • 2. Reaction of indirect hemagglutination (RNGA). This type of diagnosis is based on the ability of blood cells to connect when antigens and antibodies are located on the surface of erythrocytes;
  • Enzyme-linked immunosorbent assay (ELISA). The interaction of the antigen with the antibody is established. For a label that allows you to see the result, special enzymes are used;
  • Immunofluorescence reaction (RIF). There is a special label in the material used that leads to luminescence if the antibody reacts to the antigen;
  • Enzyme-labeled antibody reaction (REMA). The result is assessed by a label that acts as a special enzyme;
  • Intravenous allergen test. A reaction to the introduction of the helminth antigen occurs. A little antigenic solution is injected subcutaneously. The diagnosis is made after the manifestation of hyperemia and redness at the site of antigen injection;
  • Muscle biopsy. It is carried out only after the results of other examinations, there should be no positive result. With the help of microscopic analysis, biological material obtained from the area of ​​infection is studied;
  • Analysis of the meat product of infected animals. Fragments of meat are examined under a microscope. If the product is contaminated, the results show helminth capsules.

Trichinosis treatment

Since the symptoms and course of trichinosis are severe, treatment should be stopped in a short time. Treatment takes place in a stationary environment under the supervision of doctors.

During the period of illness, bed rest is recommended. One of the methods of stopping the disease is etiotropic therapy, that is, taking various drugs.

Medication for trichinosis (drugs)

Stopping and treating trichinosis involves taking anthelmintic drugs that fight the main causative agent of the disease.

These tools include:

Mebendazole. The drug disrupts the metabolism of helminths and their absorption of glucose. Due to violations of synthesis, parasites die. The drug is contraindicated for pregnant and breastfeeding women


Albendazole. The effect of the drug is almost the same as that of Mebendazole. It is known to be effective against larvae. Has the form of tablets of 0.2 grams. Pregnant women and people with diseases of the retina are contraindicated


Vermox. The drug is 90% effective. The active ingredient in the composition is mebendazole

Vermox instruction
Vermox instruction

Thiabendazole. Effective by 90%

To eliminate the symptoms of trichinosis, the following drugs are prescribed:

  • anti-inflammatory medicines - Diclofenac, Ortofen, Voltaren, Diclogen. The drugs neutralize inflammation caused by allergic reactions;
  • antipyretic drugs - Paracetamol, Aspirin, Nurofen, Ibuprofen. Reception is required at temperatures above 38 C;
  • glucocorticoids (hormonal drugs that suppress immunity and reactions to allergens).

Surgical intervention for trichinosis

Operations are not performed in case of illness, it has been established that this is impossible. Trichinosis is treated with medication.

The mechanism of infection with trichinosis in animals

Infection of the animal and the human body occurs due to the entry of helminths into the gastrointestinal tract. So, 1 kg of meat contains tens of thousands of larvae, so even a small piece is enough to become infected.

The mechanism of infection with trichinosis in animals
The mechanism of infection with trichinosis in animals

At the initial moment of invasion, trichinosis does not cause tangible harm to the body: only after 3 days the larva becomes sexually mature.

The male dies after fertilization, while viviparous females live for about 50 days. During this time, they manage to give birth to more than 1500 larvae, which are spread by the flow of lymph and blood throughout the body, including the muscles of the tongue, trunk, larynx.

Once inside, the larva begins to grow, twist in a spiral and become covered with a protective capsule.

Infection symptoms

The first symptoms of trichinosis in animals appear 5-6 days after infection. The disease proceeds against the background of the following symptoms:

  • digestive upset (vomiting and diarrhea);
  • swelling;
  • depletion of the body;
  • apathetic animal behavior.

Trichinosis disease lasts from 1 month. up to 1 year, after which it becomes chronic. Full recovery occurs only in animals with strong immunity. Infection of the human body is accompanied by gastrointestinal disorders, swelling, puffy face, high fever. The result of a dangerous disease can be a lethal outcome if trichinosis is not diagnosed in time and adequate treatment is not started.

Prevention of trichinosis in animals

The main measure to prevent the spread of the disease is trichinelloscopy. All carcasses of animals susceptible to trichinosis must be examined for infection. Veterinarians of laboratories must notify medical institutions about the fact of finding an infested animal. In case of infection on the territory of pig and fur farms, the following measures should be taken:

  • cleaning the territory of farms and nearby settlements from carcasses of small animals and garbage;
  • destruction of small rodents, stray cats and dogs;
  • exclusion of the meat of animals killed in the hunt from the diet of pigs and fur-bearing animals;
  • waste, meat of marine mammals can be fed to pigs only boiled;
  • a ban on the use of non-neutralized animal carcasses by hunters as bait

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