Trichinella spiralis is a roundworm, females are 2.5-3.5 mm long and males are 1.1 mm long. The development cycle of the worm occurs without changing hosts, within one organism - humans, pigs, rats, bears and other carnivorous and omnivorous mammals. At the same time, not a single stage of helminth development is released into the external environment.

Trichinella females are viviparous; the larvae emerge from the eggs while still in the uterus. The source of human infection is the meat of animals, in the muscles of which there is an encapsulated helminth larva.

When contaminated meat enters the stomach, the muscle fibers are digested and the larvae penetrate the intestines. In the jejunum, they penetrate the mucous membrane and molt. After 3 days they reach sexual maturity and change into males and females.

On the 5-6th day after fertilization, the female gives birth to larvae. Its lifespan is about 50 days, during which time it is capable of giving birth to up to 2 thousand larvae, then dies.

The larvae penetrate the lymphatic and circulatory systems through the intestinal walls and spread throughout the body. They finally settle only in the striated muscles.

The larvae appear in the muscles 6-9 days after infection. Having a boring stylet and secreting a special liquid, the larva penetrates the muscle tissue, which is destroyed in the process. A person experiences quite severe muscle pain due to tissue destruction.

Starting from the 6th month, the capsules become calcified and the larva can live in it for many years.

When a person’s immunity is sharply weakened, the larvae do not spread throughout the body, but remain in the intestine and penetrate the villi of the mucous membrane, where they quickly develop into adults, return to the intestinal lumen and lay larvae. There is a sharp increase in larvae in the body, which significantly worsens its condition.

What harm is done to the body?

The pathological effect of Trichinella on the body is due to:

Most often larvae are found

• in the legs of the diaphragm,
• in the masticatory muscles,
• tongue muscles,
• oculomotor muscles,
• intercostal muscles,
• pectoral, cervical, deltoid and calf muscles.

Myocardial damage occurs in cases of severe infection in the form of allergic myocarditis, which is the main cause of death.

Trichinosis

In Russia, the disease is widespread. Areas of constant surveillance of epidemics are the northern regions of the Caucasus, Krasnodar Territory. The centers of spread are pigs, and to a lesser extent rats. The main factor in infecting pigs is unboiled feed from slaughterhouses. During outbreaks, both cats and dogs can become infected.

In nature, foci of infection are maintained by animals such as wolves, bears, foxes, raccoon dogs, badgers, and wild boars.

How can you get infected?

A person becomes infected with Trichinella by eating wild animal meat or pork.

This happens when the meat is not cooked well enough. The larvae can be found in bacon, brisket, lard and sausage.

Inside a piece of meat, Trichinella larvae die at a temperature of 70⁰C.

Salting and smoking have no detrimental effect on them.

The disease is usually widespread; members of the same family or people participating, for example, in the same feast are infected.

Cases of the disease are recorded mainly in the fall.

Development of the disease

There are three phases of the pathological process:

• enzymatic-toxic, which develops 1-2 weeks after infection,
• allergic at 3-4 weeks,
• immunopathological.

In the first week after infection, inflammation of the small intestine develops under the influence of metabolic products secreted by larvae and adult Trichinella.

By the end of the first week, the larvae begin to spread en masse throughout the body through the lymphatic and blood vessels. The immune system does not react to the larvae, as it is focused on producing antibodies to the metabolic products of adults. Therefore, they spread unhindered.

By the end of the second week, the level of specific antibodies becomes so high that it leads to violent allergic reactions. Severe inflammation in the small intestine leads to the death of adults. Granulomas form around the larvae, which at this time are already settling in the muscles, from which fibrous capsules are then formed.

If the larvae linger not in the muscles, but in the brain, myocardium or lungs, then round cell infiltrates form around them, in which the larvae die. This leads to disruption of the functioning of these organs, which manifest themselves as vascular disorders.

Allergic reactions of the body are manifested by swelling, secretory activity of the mucous membranes, which leads to conjunctivitis, diarrhea, runny nose, and cough.

The phase of immune reactions during intensive infection can manifest itself as systemic vasculitis and severe organ damage. In addition, complications of trichinosis can include focal myocarditis, meningoencephalitis, and focal pneumonia.

By 5-6 weeks, inflammation in parenchymal organs (brain, lungs, etc.) is replaced by dystrophic disorders.

Symptoms

Unlike many other worm infections, trichinosis occurs with severe symptoms.

Moreover, when meat is infected with pork, the disease occurs with a shorter incubation period, pronounced symptoms and moderate damage to the body.

When infected with bear meat incubation period usually long-lasting, symptoms are moderate, but serious organ damage is observed.

This is due to the fact that these Trichinella have strain differences.

A malignant course of the disease is possible, in which death occurs on days 2-3 of the disease.

There are 5 forms of helminthiasis:

• subclinical,
• erased,
• light,
• medium-heavy,
• heavy.

Severe and subclinical course

With this course of trichinosis, the incubation period is 4-5 weeks.

This form of the disease is registered in approximately 1/3 of those infected and is manifested by the following symptoms:

low-grade fever,

mild muscle pain,

slight swelling of the face,

general malaise.

In the blood there is eosinophilia (7-12%), normal leukocytes.

Light and medium-heavy forms

For mild cases

• the incubation period is 4 weeks,
• body temperature rises to 38-39⁰С.

From the first days the following symptoms appear:

• headache,
• general malaise,
• moderate pain in the calf, lumbar, masticatory muscles,
• swelling of the eyelids,
• puffiness of the face.

After 1-2 days, the body temperature drops to low-grade fever. Painful symptoms go away without treatment within 1-2 weeks.

The moderate form of the disease begins with a sharp increase in body temperature to 39-40⁰C with a gradual decrease over 2-3 hours to 38-38.5⁰C and persists throughout the first week, becoming subfebrile in the second week of the disease.

The incubation period for this form is 2-3 weeks.

Fever is accompanied by intense pain in the calf muscles, lumbar, occipital, chewing, and extraocular muscles.

Characteristic symptoms:

• pronounced swelling of the eyelids,
• puffiness of the face,
• conjunctivitis,
• rash,
• stomach ache,
• vomit,
• diarrhea.

With bronchopulmonary damage the following appear:

• bronchitis,
• pneumonia,
• pleurisy,
• heartbeat,
• dyspnea.

IN chemical analysis blood changes are observed:

• hypoproteinemia,
• hypoalbuminemia,
• increase in α₂-globulins, γ-globulins,
• decreased aldolase activity.

In the general blood test - leukocytosis, eosinophilia (25-60%), in the initial period of the disease there is a decrease in ESR.

Severe forms

The incubation period is short and lasts 7-10 days; in very severe cases with pronounced intestinal symptoms, it is reduced to 1-3 days.

High body temperature up to 40-41⁰С lasts 2-3 weeks and is accompanied by

• severe headaches,
• delusional
• excitement.

Intense pain in the calf, eye, chewing muscles, in the tongue, with the development of the disease in the muscles of the lower back, shoulder girdle, accompanied by cramps up to complete loss of mobility.

Multiple swelling of the trunk, limbs, internal organs,
the membranes of the brain lead to dysfunction of the central nervous system.

A rash appears on the skin of the face, torso, and extensor surfaces of the limbs.

Often observed

• nausea,
• vomit,
• stomach ache,
• loose stool mixed with mucus and blood.

When the respiratory system is damaged, bronchitis develops asthmatic component, diffuse pneumonia, with painful cough, shortness of breath and bluish skin.

Often there are lesions of the central nervous system, which manifest themselves:

• headaches,
• insomnia,
• delusional
• convulsions,
• mental disorders,
• epileptic seizures,
• paralysis,
• deafness,
• bulging eyes,
• blindness.

In the malignant course of trichinosis, the death of patients is possible within several days as a result of ulcerative-necrotic damage to the intestines and bleeding. This development of the disease is associated with the rapid and intense development of allergic reactions.

Symptoms in children

In children, mild forms of the disease predominate, often erased and subclinical.

The temperature reaction is weakly expressed.

The main symptoms are moderate:

• swelling,
• muscle pain,
• abdominal pain.

Changes in blood tests are minor.

Doctors believe that this course of trichinosis in children is due to the lower intensity of infection and the low immune reactivity of the body.

Diagnostics

When diagnosing, an important place is given to the survey. If it turns out that the sick people ate meat, then if there are remains of this meat, it is examined for the presence of Trichinella larvae.

With the artificial digestion method, 10 g of crushed muscle mass is placed in a flask and filled with artificial gastric juice. After 4 hours, the sediment is examined under a microscope.

200 larvae per 1 g muscle tissue correspond to a moderate degree of infection,
500 - intense, more than 500 - super intense.

During compressor trichinoscopy, pieces of muscle tissue the size of oat grains are placed between glasses and compressed with screws. The crushed pieces are examined under a microscope.

From the third week of the disease, the diagnosis is confirmed by a serological method; ELISA is often used. 2 sera taken at an interval of 2-3 weeks are examined.

Treatment

Patients with trichinosis are treated in a hospital. The most effective treatment is in the first 2 weeks of infection, until the larvae are encapsulated.

After encapsulation, the effectiveness of treatment decreases.

albendazole for a course of 8-14 days or mebendazole for a course of 5-14 days.

To reduce symptoms, antipyretic and anti-inflammatory drugs are used:

• diclofenac,
• ibuprofen.

If glucocorticosteroids are not indicated for the patient, then use antihistamines: promethazine, chloropyramine.

In case of severe intestinal manifestations, it is necessary to correct the water-electrolyte balance with potassium chloride or potassium and magnesium aspartate.

Severe swelling is relieved with furosemide intramuscularly or intravenously or spironolacone orally.

If necessary, protein balance is corrected.

After suffering moderate and severe trichinosis, patients need restorative treatment:

• taking vitamins,
• physiotherapy (for muscle contractures),
• anabolic agents for acute exhaustion.

Forecast

In mild forms of infection, complete recovery occurs within 1-2 months. In moderate forms, exacerbations in the form of muscle pain may occur after a course of treatment. Working capacity is restored after 4-6 months. In case of severe trichinosis, full working capacity is restored after 6-12 months.

Prevention

The main preventive measures are

• purchasing meat that has passed veterinary control,
• sufficient heat treatment of meat (the temperature of the meat inside the piece should be at least 70 degrees),
• in the absence of a guarantee of sanitary and veterinary examination, the meat should be subjected to heat treatment for at least 2.5 hours,
• keep lard frozen for at least 1 month before salting or smoking.

The invention relates to the field of agriculture, namely to veterinary helminthology and sanitation, and can be used for disinfestation of the carcasses of some game animals from trichinosis infection. The neutralization method can also be used in feed production when preparing bait or feed from raw meat infested with Trichinella larvae both in game nurseries and in specially protected areas.

For a long time it was believed that low temperatures do not kill Trichinella larvae in meat, although they have an adverse effect on them. Wild carnivorous mammals are often infected with low-temperature-resistant Trichinella larvae. When freezing wild animal meat in household refrigerators at a temperature of minus 12°C, Trichinella larvae of individual cold-resistant Trichinella isolates long time remain viable and invasive.

According to the recommendations of the International Commission on Trichinosis (ICT), to inactivate the larvae of Trichinella spiralis in pork, the minimum freezing time at minus 17.8°C is 106 hours, at minus 23.3°C - 63 hours, and at minus 28.9°C - 35 hours. Depending on the size of the pieces, it is recommended to freeze pork at minus 15°C for at least 3-4 weeks.

SanPiN 3.2 regulates the freezing of pork carcasses at an air temperature in the chamber of minus 12°C for 10 days.

Development of high-quality and fast way neutralizing the carcasses of commercial animals from trichinosis invasion is an urgent task today for the prevention of helminthiasis.

There are known methods for neutralizing Trichinella larvae in muscle tissue: low and high temperatures, through salting and smoking, vacuum drying, solutions of acids and alkalis, ionizing radiation, microwave radiation, ultrasound, using electric discharges, drying and long-term storage of meat. The disadvantages of using these methods of neutralization are long exposure time, the lowest efficiency of neutralization, the impossibility of further technological processing of carcasses or require additional processing (grinding muscle tissue, chopping into half carcasses, chopping pieces of meat no more than 8 cm thick) for neutralization.

The closest way is physical method neutralization at low temperatures. According to the recommendations for the neutralization of pork, meat slaughterhouse waste and carcasses of fur-bearing animals, when Trichinella are detected in the first series of experiments (according to A.S. Bessonov, 1966), the neutralization of Trichinella larvae, which are not resistant to low temperatures, was carried out only in pork meat (in headless and primarily processed carcasses (piglets 3-9.5 months old) and half-carcasses (swine mixtures) of pigs), in the above experiments an effective neutralization temperature of minus 50°C was used.

The purpose of the present invention is to develop a faster and effective way neutralization of freeze-resistant Trichinella larvae in the carcasses of commercial fur-bearing animals without additional technological processing of raw meat (cutting, grinding into minced meat). The secondary objective of the invention was to develop a safe method of feeding raw meat that would stop the spread of trichinosis with animal carcasses, and due to this, sanitary and hygienic conditions were gradually improved and some environmental issues were resolved in nurseries, hunting grounds and in specially protected areas. Trichinosis would also be prevented in domestic animals, in particular in hunting, guard, and service dogs.

The proposed method of neutralizing meat products for the prevention of trichinosis in game animals by deep freezing trichinella-infested animals used for food is simple in execution, technically feasible both in veterinary and sanitary examination laboratories, and in the feed kitchens of animal farms or at home, where there are low-temperature freezers or freezers. The method does not require special training of operating personnel, since freezers are used for their intended purpose (deep freezing of carcasses), but only requires maintaining the proposed specified technological parameters - freezing time, weight of processed meat products.

The effectiveness of the proposed method for neutralizing Trichinella larvae in the carcasses of some fur-bearing animals is reflected in the following examples.

Example 1. Resistance to low temperatures of Trichinella larvae in the muscle tissue of the common fox. When studying the resistance to low temperatures of Trichinella larvae isolated from a common fox shot in the Ryazan region, it turned out that they remained viable and invasive for a long time. The fox carcass was divided into samples 2-5 cm thick and weighing no more than 15 g, which were placed in freezers at minus 16°C and 23°C. Samples were examined after 8, 19, 42, 78, 107, 134, 157 and 192 days of continuous freezing at these temperature conditions.

During the study, it was found that when muscle samples from the common fox were frozen at minus 16°C for 107 days, the number of viable Trichinella larvae decreased from 96% at the beginning of the experiment to 80%, and at minus 23°C to 65%. During this period, Trichinella larvae remained invasive, which was confirmed by the results of a bioassay on white mice.

However, the invasiveness of Trichinella larvae after freezing for mice - bioassays at the same dose of infection with viable larvae (10 Trichinella larvae per 1 g of animal weight) decreased: at minus 16°C the intensity of invasion of white mice decreased to 67 larvae per 1 g of animal weight, and at minus 23°C up to 43 larvae per 1 g of weight.

The viability of Trichinella larvae remained throughout the entire period of freezing for 24 hours at minus 16°C and 134 days at minus 23°C. The experiment was terminated due to the lack of sufficient muscle tissue samples from the fox. The high frost resistance of Trichinella larvae in the muscle tissue of the common fox characterizes their belonging to a helminth species resistant to negative temperatures.

Example 2. Experience in neutralizing carcasses of fur-bearing commercial animals naturally infested with capsular trichinella. Infested trichinosis material consisted of carcasses without skins different types game animals caught on hunting grounds (foxes, raccoon dogs, martens). The presence of invasion and the degree of invasion of the material were determined by compressor trichinoscopy. To do this, from each muscle sample weighing about 50 g, 24 sections of muscle the size of an oat grain (with a total weight of about 0.7-1.0 g) were cut along the muscle fibers using curved scissors. The sections were compressed between compressor glasses and microscoped at low microscope magnification. The intensity of invasion was determined by counting Trichinella larvae in 1 g of muscle tissue. During the production test for neutralization, the carcasses of infested animals were isolated from uninfected carcasses, packaged separately from each other and tied in plastic bags with a volume of 100 US dollars.

Bags with carcasses of animals infected with Trichinella larvae were placed in the freezer compartment, which was previously turned on before neutralization (8 hours before the start of work). The invasive material was kept in the freezer for a certain time depending on the type and weight of the animal carcass (Table).

To neutralize the invasive material, it should be placed in the freezer gradually. From 30 g to 20 kg were placed in an empty freezer with a volume of 2 5 m 3. In this case, the invasive material was filled gradually, adding 10 kg portions every 4 hours of operation of the freezer, but not more often.

Quality control of the neutralization of invasive material in the muscle tissue of animals after thawing of carcasses for the viability and invasiveness of the larvae of the causative agent of trichinosis was carried out according to the method for determining the viability and invasiveness of Trichinella larvae. When the larvae were isolated by digestion in artificial gastric juice, it turned out that the isolated larvae were non-viable.

Example 3. Conducting a biological test on laboratory animals after neutralizing Trichinella larvae by deep freezing. After neutralization by deep freezing at minus 70°C of carcasses of commercial animals naturally infested with capsular larvae of Trichinella (fox and raccoon dog for 18 hours, martens - 6, rats - 5, mice - 1) from the causative agent of trichinosis, a biological test was carried out on laboratory animals (white mongrel mice). Trichinosis animal carcasses frozen at minus 23°C for the same period of time as in the experimental group and carcasses not subject to freezing served as controls. The muscle tissue of the animals was dissected from the bones and ground in a meat grinder. The finished minced meat was placed in mill gas (mesh size 1 mm). Then the mill gas with minced meat was placed in freshly prepared gastric juice (per 1 liter of distilled water: 10 ml of concentrated hydrochloric acid and 3 g of pepsin activity units). The ratio of minced meat and gastric juice should be 1:20. Minced meat prepared for artificial digestion in gastric juice was placed in a thermostat at 37°C for 18 hours. After exposure, the sediment was washed three times in distilled water. An isolated suspension of Trichinella larvae after artificial fermentation from each group of animals was administered at a dose of 5 larvae per 1 g of white outbred mouse weight. Next, laboratory mice of each group were kept according to generally accepted sanitary and veterinary rules. After 45 days, the laboratory animals were euthanized using medicinal ether in a crystallizer with a ground-in lid. To diagnose trichinosis in mice, compressor trichinoscopy was performed. In the experimental group of laboratory animals, Trichinella larvae did not develop in the muscle tissue; in both control groups of white mice, capsular Trichinella larvae were registered.

The proposed method, which includes the use of freezers with a significantly low cooling temperature, ensures rapid and effective neutralization of Trichinella larvae in muscle tissue.

1. Bessonov A.S. Epizootology (epidemiology) and prevention of trichinosis. Mintos, Vilnius, 1972.p.

3. Veterinary legislation. - M., 1988. - T.IV.s.

5. Trichinosis. Scientific works of VASKHNIL, Moscow “Kolos”, 1976, 338 p.

Trichinosis - “harmful” meat

November and December are traditionally rich in holidays. And that means festive feasts. They are usually an excellent occasion to demonstrate a wide variety of culinary delights. Housewives put village delicacies on the table - delicious circles of “finger phanoi” sausages, pink slices of smoked pork. Male breadwinners are concerned with the supply of hunting trophies. It’s a pleasure to offer guests roast wild boar or juicy bear chops. We have nothing against it. In the event that, along with a selected piece of meat, you do not acquire a disease, the consequences of which can be very sad.

“A terrible demon”, “a terrible enemy of man” - this is how the infectious disease trichinosis was called in the middle of the last century, from which entire families died out in Europe. Nowadays, such large outbreaks of trichinosis almost never occur, but this disease is not uncommon among the population of Belarus.

Almost every year in Minsk from November to February, during the period of mass slaughter of domestic pigs and hunting of wild animals (boars, foxes), cases of trichinosis are recorded. Moreover, people began to get sick much more often. If earlier we were talking about isolated cases, now we count dozens. The reason for this is elementary ignorance, and even more often, the frivolity so characteristic of us: “ maybe it will blow through, but I’ll save money».

Let’s say right away that a “thrifty” housewife, having fed her family pork infected with Trichinella, will soon be forced to borrow money for medicine for the whole family. And it’s also good if there are no tragic outcomes - untreated trichinosis can lead to the death of the patient.

So let's take a closer look at what this disease is and how to avoid it.

People most often become ill by eating contaminated pork and home-cooked sausages that have not undergone veterinary examination. There are a lot of pathogenic larvae in the muscles of the animal; they are literally “stuffed” with them. For example, in 1 g of muscle tissue of a brown bear, up to 200 Trichinella larvae are found, which can only be seen under a microscope.

Meat affected by trichinosis does not differ in any external signs (smell, color, consistency) from ordinary benign meat. However, the larvae retain their ability to cause disease for years; in animal corpses they die when exposed only to very high or very low temperatures.

The main cause of human illness is the consumption of contaminated meat without sufficient heat treatment or meat products that are deliberately cooked raw or half-baked. The pathogens enter the body of wild and domestic animals when they eat the corpses of rodents and other living creatures affected by trichinosis, and are deposited in the muscle fibers in the form of spirals covered with a calcareous shell.

In the stomach of a person who has consumed contaminated meat, the lime capsules dissolve, Trichinella penetrates the intestinal wall and begins to lay larvae, which are carried by blood and lymph throughout the body and settle in the muscles.

The disease manifests itself after a certain period (from three days to 4–5 weeks). A sick person begins to complain of severe muscle pain. A rash appears on the body, breathing, swallowing and eye movement become difficult and painful. This disease is characterized by the appearance of swelling on the face, hence its popular name “puffiness”. In severe cases, damage to the respiratory, cardiovascular and nervous systems is possible.

To avoid infection, it is necessary to carry out veterinary inspection of each carcass of a killed pig or wild boar by trichinoscopy. It is carried out by veterinary and sanitary laboratories located in each regional center and in large markets.

For trichinoscopy, pieces of meat most affected by Trichinella (diaphragm, intercostal, chewing and tongue muscles) should be delivered. If at least one trichinella is detected in the cuts, the meat is considered unfit for food and must be destroyed. In this case, the outer fat can be eaten only when melted, and the inner fat can be eaten without restrictions.

Meat needs to be controlled because in Belarus, from time immemorial, dried sausage and polendvitsa have been made from pork and consumed practically without any heat treatment, and Trichinella can remain viable in it even after prolonged cooking of a piece of meat.

When you buy meat from a state trade, you are guaranteed that it has been tested for trichinosis. If you purchased meat at the market, make sure it is marked. Under no circumstances should you buy meat or lard, as well as home-made sausages from random people and in unidentified places.

For personal prevention, meat or lard should be thoroughly cooked or fried in small pieces. The death of Trichinella occurs only when pieces of meat no more than 8 cm thick are cooked for 2.5 hours. Salting, smoking or freezing meat and lard does not kill the larvae, even with prolonged exposure.

Finally, a special warning to hunters. Remember that your hobby “can bring not only pleasure, but also trouble. In most cases, trichinosis is associated with consumption of wild boar meat. So don’t be lazy to first check your “trophies” in the veterinary laboratory, and only then set the table. This simple precaution will prevent serious threats to your health.

A. Gladky, chief state sanitary doctor of the Leninsky district of Minsk, Y. Ignatova, hygienist.

Magazine "Health and Success", No. 11, 1997.

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Trichinosis in humans

Prevalence of trichinosis

Reasons for the widespread prevalence of trichinosis:

The pathogen's good adaptability to high and low temperatures ensured its residence in many climatic zones;

The human body is extremely susceptible to this disease;

Group outbreaks of helminthiasis are not uncommon among members of one team or one family who have consumed meat with Trichinella;

Repeated cases of infection occur due to unstable immunity formed after the initial invasion.

Methods of infection with trichinosis

The development of trichinosis in the human body after infection:

Time since infection

The larva freed from the capsule penetrates into the mucous membrane of the stomach or duodenum and the underlying connective tissue.

The larva develops into a mature worm.

A mature female worm lays larvae (one female can produce from 100 to 2000 new worms).

The larvae get into blood vessels and are delivered through the bloodstream to the muscles.

The time during which an adult female worm is able to lay larvae.

17-18 days from the moment the female deposits larvae

The larvae mature in the muscles and become infective to a new host.

3-4 weeks from the moment the female lays larvae

The larva is covered with a capsule. A year later, the capsules become calcified.

This is the period during which the larva in the form of a capsule is able to survive in the host’s muscles.

The first signs and symptoms of trichinosis

Incubation period of trichinosis. Lasts from 5 to 30 days, more often days. There are no symptoms of the disease. There is a pattern - the more severe the form of helminthiasis, the longer the latent (hidden) period.

High period. A long period of development of symptoms indicates the development of a severe form of trichinosis.

Mild and moderate form - symptoms:

Hyperthermia. The temperature rises slightly, more than 37°C, the daily amplitude fluctuates within 1°C.

Swelling on the body and limbs. Its cause is an allergic reaction to the introduction of a foreign protein. A characteristic symptom is a “frog face” in the patient.

Skin rash. Has different forms:

In the form of allergic urticaria - pink blisters of various sizes that turn pale when pressed;

Itchy blisters raised above the surface of the skin (utricar rash);

Groups of plaques merging with each other (papular rash).

Complications in severe forms of trichinosis:

Meningoencephalitis is an inflammation of the membranes of the brain.

Inflammation of the lungs (eosinophilic pneumonia). The disease is caused by an increased concentration of eosinophils, products of an allergic reaction, in the lung tissue. Pleurisy and symptoms of bronchial asthma may develop.

Myocarditis is inflammation of the myocardium due to allergies and excessive immune response. More often than other complications it causes death in patients.

Nephritis is inflammation of the kidney tissue.

Intense pain in the muscles leads to partial or complete impairment of mobility.

Mortality in severe forms of the disease is 10-30% of the total number of patients. The most common period for deaths to occur is 4-8 weeks from the onset of infection. In milder forms, patients recover after 5-6 weeks.

Symptoms of trichinosis depending on the stage of the disease

Time since infection

Trichinosis invasion (penetration into the body)

Trichinella larvae that enter the body orally are in small intestine. They become attached to the mucous membrane, causing inflammation of the intestinal wall. Within 55 days, the development of larvae into sexually mature individuals occurs in the small intestine, their fertilization and the emergence of a new generation of larvae. One female Trichinella produces up to one and a half thousand individuals.

Symptoms of the early stage of trichinosis:

Alternating diarrhea with constipation;

Pain in the epigastric region;

Nausea and vomiting;

Dissemination (spread of larvae throughout the body)

The larvae begin their migration in the tissues of the body, penetrating into the muscles. They make their way from the intestine through the blood vessels and lymphatic vessels. After penetration into the blood, Trichinella larvae become attached to muscle fibers. They develop and grow, releasing allergens into the blood. Intoxication begins in the body and develops allergic reactions.

Periorbital edema is a characteristic symptom of trichinosis. The eye muscles affected by the larvae become inflamed and swell from a large amount of interstitial fluid. The upper and lower eyelids and bridge of the nose swell, and pain appears when moving the eyes.

Hemorrhages in the retina and under the conjunctiva of the eyes are caused by damage to the walls of blood vessels by Trichinella. Indispensable symptoms are itching and lacrimation.

Hyperthermia lasts from 1 to 2 weeks and is a reaction to the action of toxins secreted by helminths. Body temperature can reach 38-40°C.

Puffiness of facial tissues is caused by the entry of Trichinella into the muscles of the tongue and chewing muscles. The skin of the face is affected by rashes. Edema can spread to brain tissue and lung parenchyma.

Headache is a reaction to toxic damage to the brain.

Muscle pain is a consequence of muscle damage by Trichinella. Starts from the limbs, spreads to the neck and shoulders. The higher the concentration of helminths in the body, the more intense the pain and the more limited movements are.

Disruption of the central nervous system - insomnia, depression are caused by damage to nerve cells.

Dysphagia – problems swallowing due to the proliferation of larvae in the masticatory and swallowing muscles.

Respiratory problems, cough - symptoms appear due to sputum production due to an allergic reaction, a conflict between antigens and antibodies.

6 weeks to 6 months after infection

During this period, tissue regeneration occurs. The larvae reach a size of 0.8 mm and take on a spiral shape. The foreign inclusion (larva) is fenced off by the capsule from the muscle tissue and stops its development. Trichinella toxins do not enter the body, the symptoms of the disease become less intense and gradually cease. The capsule becomes calcified, these salts can destroy the larva. Sometimes the Trichinella larva remains viable for up to 25 years, without affecting a person’s well-being.

Symptoms of the regeneration phase:

Restoring the functions of the affected posterior organs;

Muscle pain lasts up to 2 months;

An increased concentration of eosinophils is recorded up to 3 months.

Symptoms of the disease can be blurred and disguised as other diseases. There are three signs of trichinosis that are always recorded by a doctor after eating contaminated meat:

An increase in the number of eosinophils in the blood;

Swelling of the tissue around the eyes (periorbital edema)

Symptoms of trichinosis in humans may be similar to manifestations of myositis, allergies, infectious disease. This picture leads to the fact that the patient does not suspect that he has helminthiasis.

Symptoms of trichinosis in children

To become infected, it is enough for a child to eat a small piece of meat with trichinella weighing 100 g, which has not undergone full heat treatment. The latent period lasts from 5 to 45 days. The shorter this period, the more severe the form of the disease in the child.

Symptoms at an early stage. Lasts 7-14 days, after recovery there are minor symptoms for 7-10 days.

Hyperthermia up to 38.5°C:

Slight puffiness of the face;

Mild muscle pain;

Increase in eosinophil concentration by 10-12%.

Symptoms are at a moderate stage. The acute period lasts up to 3 weeks, rehabilitation – 2-3 weeks after recovery.

Hyperthermia up to 40°C, antipyretic drugs reduce it by no more than 1°C;

Pain in muscles, joints, stomach and throat;

results general analysis blood: ESR is increased (above 17 mm/h), leukocytes are increased (up to 8.8·10 9 /l), the concentration of eosinophils is increased to 25-40%.

Symptoms at a severe stage. He is being treated in the infectious diseases department of the hospital; without therapy, the child may die.

Hyperthermia up to 41°C;

Enlarged liver and spleen;

Central nervous system disorders: delirium, agitation, epileptic seizures;

Seizures severe pain in a stomach;

Severe muscle pain complicated by cramps;

Subcutaneous hemorrhages and rash;

General blood test indicators: Leukocytes up to 30-40x10 9 /l; ESR domm/h; eosinophil concentration up to 80 - 90%;

Casts and proteins in the urine.

Treatment of trichinosis in children is carried out with anthelmintic drugs (Tiabendazole, Vermox) in accordance with the body weight and age of the child.

Medicines for symptomatic treatment trichinosis:

Ibuprofen, Paracetamol - to reduce temperature, relieve pain;

Cetrin, Loratadine - antihistamines to reduce intoxication and allergy symptoms;

Papaverine, No-shpa - antispasmodics to reduce pain;

Vitamins of groups C and B to improve immunity.

Rehabilitation after illness is carried out through massage sessions, baths with sea ​​salt And medicinal herbs, complex of therapeutic gymnastics.

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Diagnosis of trichinosis

General blood analysis. With trichinosis in a person, the content of eosinophils, a type of white blood cell, increases significantly in the blood. The concentration of white blood cells most often increases with severe allergic reactions, including allergies that accompany trichinosis.

Changes in blood composition diagnosed with trichinosis:

The number of eosinophils reaches from 50 to 80% of the total number of leukocytes;

An increase in the concentration of leukocytes is a sign of activation of the immune system and the presence of an inflammatory process in the body.

These symptoms appear immediately after infection and persist 2-3 months after recovery.

Serological diagnosis. An analysis of the blood reaction to the addition of antigens obtained from nematode larvae is carried out. Antibodies to them are formed as a reaction to the introduction of helminths.

Types of serological diagnostics:

Complement fixation reaction

If there are antibodies in the patient’s blood, they combine with the antigen and attach a complement molecule, a special substance involved in immune reactions. In this case, the reaction will be considered positive.

Indirect hemagglutination reaction

It is based on the ability of red blood cells to stick together when there is an antibody and antigen on their surface.

A reaction is carried out between antibodies and antigens. Special enzymes serve as a marker to evaluate the result.

The material contains a special label that causes it to glow after the antibody reacts with the antigen.

Reaction of enzyme-labeled antibodies.

A special label, which is an enzyme, allows you to evaluate the result.

Intravenous allergy test. It is carried out to provoke an allergic reaction in response to the introduction of trichinosis antigen. A portion of the antigen solution is injected under the skin. The presence of the disease is diagnosed by the appearance of hyperemia and redness at the injection site. This method can diagnose trichinosis starting from 2 weeks of nematode infection. A positive allergy test result lasts for 5-10 years.

Muscle biopsy. It is carried out in the absence of a positive result from other research methods. The biomaterial obtained with a needle from the patient’s muscle is examined under a microscope.

Study of meat from sick animals. At multiple magnification, the meat of the animal, the suspected source of infection, is examined. Using a microscope, capsules with larvae are detected in the tissues of a sick animal.

Treatment of trichinosis

Anthelmintic drugs (treatment aimed at combating the causative agent of the disease):

Indications and effects

It disrupts the absorption of glucose by worms and the synthesis of ATP, the main carrier of energy, in their bodies. As a result of metabolic disorders, the worms die.

Mebendazole is contraindicated in pregnant and nursing mothers.

0.3 - 0.6 g (1 - 2 tablets of 0.1 g three times a day) for 10 - 14 days.

(Reference Vidal, 2010)

It works almost the same way as Mebendazole. Most active against larval forms of worms. Available in the form of tablets of 0.2 grams.

Contraindicated in pregnancy and retinal diseases.

Take at the rate of 10 mg per kilogram of the patient’s body weight for 10 to 14 days.

Active substance; mebendazole. Efficiency is 90%

Adults take 100 mg 3 times a day for the first three days. The next 10 days – 500 mg 3 times a day

Children under 7 years of age: 25 mg of the drug 3 times a day.

Children aged 7 – 9 years: 3 times a day, 50 mg.

Children over 10 years old: take 100 mg 2-3 times a day for the first three days, then 500 mg 3 times a day for 10 days.

Take after meals.

during the first three days; 100 mg 3 times a day;

next 10 days; 500 mg 3 times a day.

25 mg of the drug 3 times a day.

Children aged 7; 9 years:

3 times a day, 50 mg.

during the first three days; 100 mg 2 – 3 times a day;

then for 10 days, 500 mg 3 times a day.

Take after meals.

(;Complete reference book of an infectious disease specialist; edited by DMN, prof., corresponding member of RAE and REA Eliseeva Yu.Yu.,; Eksmo;, 2007)

Efficiency is 90%.

Dose for children and adults – 25 mg per kg body weight (dose (mg) = body weight (kg) * 25). Divide into 2 doses every 12 hours. The course of treatment is continued for 3–5 days, after which, according to indications, it is repeated after 7 days (as prescribed by a doctor).

Take one hour after meals.

(“Complete reference book of an infectious disease specialist”, edited by DMN, prof., corresponding member of RAE and REA Eliseeva Yu.Yu., “Eksmo”, 2007)

Treatment of trichinosis symptoms

Anti-inflammatory drugs (Voltaren, Diclofenac, Diclogen, Ortofen)

They help cope with inflammation that was caused by allergic reactions in the patient’s body.

As prescribed by a doctor.

Antipyretics (Paracetamol, Aspirin, Acetylsalicylic acid, Nurofen, Ibuprofen)

Indicated when body temperature rises above 38;C.

As prescribed by a doctor.

Preparations of hormones of the adrenal cortex - glucocorticoids

Hormonal agents that suppress the immune system and allergic reactions.

Hormonal drugs used only strictly as prescribed by a doctor.

High probability of death, frequent progression of the disease to a severe form, a large number of complications are good reasons for treating trichinosis exclusively in a hospital setting. Despite this, from 10 to 30% of cases of the disease are fatal.

Patients with severe muscle damage require careful care, as patients are completely immobilized and bedridden. To restore mobility, patients are rehabilitated using massage and physiotherapeutic methods.

Symptomatic treatment of trichinosis in humans is supplemented with vitamin therapy, drugs to stimulate blood circulation, to protect the liver and brain (if these organs are affected).

Prevention of trichinosis

Measures to prevent trichinosis:

Cooking meat (especially pork) should be done at a high temperature - at least 74°C inside the piece of meat for at least 15 seconds. Under such conditions, the Trichinella larvae will certainly die if they have not yet become covered with a calcified capsule. Otherwise, the larvae will not be harmed even with such heating. The larvae manage to become covered with a capsule during a long course of the disease in an animal that carries Trichinella.

An effective way to destroy Trichinella is freezing for 20 days at -15°C, or holding for three days at -20°C.

When breeding pigs, they should not be allowed to graze freely to prevent animals from eating contaminated carrion. It is necessary to regularly destroy rats in the place where the animals are and in the farmyard.

Mass events to prevent outbreaks of trichinosis

Rospotrebnadzor systematically monitors the living conditions of animals intended for breeding for meat. Meat cannot be sold without testing it for trichinosis. Such control is carried out at the market and in specialized stores. The safety of meat sold in spontaneous retail outlets is not guaranteed.

How to test meat for trichinosis?

Trichinella larvae are found in many animal species. Meat consumed by humans must undergo epidemic control. The most dangerous types of meat are pork, bear meat, and wild boar meat.

The appearance of contaminated meat is practically no different from that of a healthy carcass. The concentration of trichinella in the affected tissue reaches 200 pieces per 1 gram. Meat examination is carried out in a laboratory using a microscope. After analysis, a special mark is placed on the carcass.

Where can a test for trichinosis be done?

At the sanitary and epidemiological station or at the veterinary laboratory of the food market, samples are taken from the animal carcass. Samples of no more than 5 g are taken from areas of increased blood supply: masticatory muscles, tongue, intercostal muscles, diaphragm.

Even one detected trichinella is a reason for the destruction of the entire carcass, which from now on is considered unfit for food.

There is no veterinary laboratory control in spontaneous markets, during mass slaughter of livestock, or when eating hunting trophies. Unfortunately, Trichinella can be found in 30% of meat considered edible. Prevention of infection is thorough cooking of meat. This is especially true when eating game in regions where trichinosis is endemic.

How to cook meat to prevent infection with trichinosis?

The main thing is to reach a temperature of 80°C for 15 minutes throughout the entire thickness of the piece.

The best way to cook meat:

Boil meat for 2.5 hours, cut into pieces no more than 8 cm thick;

Frying and stewing meat for 1.5 hours (pieces should not be thicker than 2.5 cm);

Lard is allowed to be consumed only in melted form.

Dangerous meat products:

Homemade and raw smoked sausages;

Meat frozen at an insufficiently low temperature;

Dishes made from minced meat;

Raw lard and meat;

Steaks with blood;

The symptoms of toxocariasis are so diverse that doctors practicing in various branches of medicine - neurologists, ophthalmologists, hematologists, gastroenterologists, and therapists - can encounter its manifestations. Although researchers called humans an “ecological dead end” of toxocariasis, because it is unusual.

In case of pinworm infection, all close relatives of the infected person are subject to preventive treatment. Testing for the presence of pinworms often gives a false negative result. The ease of infection with enterobiasis through household items and shared bedding, contact with animals and handshakes, as well.

The information on the site is intended for informational purposes only and does not encourage self-treatment, consultation with a doctor is required!

Trichinella larvae can be found in the striated muscle fibers of about 150 animal species, mainly pigs and wild boars, but also, in particular, dogs, cats, horses, bears, nutria, wolves or badgers. Human infection occurs through consumption of their meat, raw or subjected to improper heat treatment.

• fever up to 39 °C,
• increased sweating,
• chills,
• swelling and pain of the lymph nodes,
• redness and itching of the skin,
• cough,
• muscle pain.

As trichinosis progresses, other symptoms appear. A characteristic symptom The disease is allergic vasculitis, expressed by petechiae, swelling of the eyelids and orbital tissue; over time, pain in the eyes, hemorrhages in the eyeball, or blurred vision may also appear. Sometimes a rash appears on the skin.

In mild cases of trichinosis, most symptoms disappear after a few months. In severe cases of the disease, when the larvae begin to spread throughout the body, it can cause inflammation of the heart muscle, pneumonia, nephritis, meningitis, damage hearing aid or problems with the central nervous system. Severe forms of trichinosis can sometimes be fatal.

How to avoid getting infected with trichinosis

Trichinosis: at what temperature do the larvae die?

It is necessary to follow the rules of hygiene - wash knives, dishes and cutting boards that have come into contact with raw meat.

Trichinosis - treatment

Trichinosis is usually treated with pharmaceutical drugs, the most commonly used being mebendazole, albendazole and thiabendazole. The course of taking the drugs lasts for 5-10 days. However, they should not be taken by pregnant women. In the treatment of complications of the disease - inflammatory processes of the myocardium, lungs or brain - corticosteroids are often recommended. Trichinosis is accompanied by a variety of pain, especially muscle pain, which can be relieved with aspirin or ibuprofen. Sometimes nonsteroidal anti-inflammatory drugs are more effective in relieving pain.

As long as fever and others acute symptoms will not disappear, bed rest is recommended.

Trichinosis in hunters

The invention relates to the field of agriculture, namely to veterinary helminthology and sanitation, and can be used for disinfestation of the carcasses of some game animals from trichinosis infection. The neutralization method can also be used in feed production when preparing bait or feed from raw meat infested with Trichinella larvae both in game nurseries and in specially protected areas.

For a long time it was believed that low temperatures do not kill Trichinella larvae in meat, although they have an adverse effect on them. Wild carnivorous mammals are often infected with low-temperature-resistant Trichinella larvae. When wild animal meat is frozen in household refrigerators at a temperature of minus 12°C, Trichinella larvae of individual cold-resistant Trichinella isolates remain viable and invasive for a long time.

According to the recommendations of the International Commission on Trichinosis (ICT), to inactivate the larvae of Trichinella spiralis in pork, the minimum freezing time at minus 17.8°C is 106 hours, at minus 23.3°C - 63 hours, and at minus 28.9°C - 35 hours. Depending on the size of the pieces, it is recommended to freeze pork at minus 15°C for at least 3-4 weeks.

SanPiN 3.2.1333-03 regulates the freezing of pork carcasses at an air temperature in the chamber of minus 12°C for 10 days.

The development of a high-quality and quick method for neutralizing the carcasses of commercial animals from trichinosis invasion is an urgent task today in the prevention of helminthiasis.

There are known methods for neutralizing Trichinella larvae in muscle tissue: low and high temperatures, through salting and smoking, vacuum drying, solutions of acids and alkalis, ionizing radiation, microwave radiation, ultrasound, using electric discharges, drying and long-term storage of meat. The disadvantages of using these methods of neutralization are long exposure time, the lowest efficiency of neutralization, the impossibility of further technological processing of carcasses or require additional processing (grinding muscle tissue, chopping into half carcasses, chopping pieces of meat no more than 8 cm thick) for neutralization.

The closest method is the physical method of neutralization at low temperatures. According to the recommendations for the neutralization of pork, meat slaughterhouse waste and carcasses of fur-bearing animals, when Trichinella are detected in the first series of experiments (according to A.S. Bessonov, 1966), the neutralization of Trichinella larvae, which are not resistant to low temperatures, was carried out only in pork meat (in headless and primarily processed carcasses (piglets 3-9.5 months old) and half-carcasses (sows 14-24 months old) of pigs), in the above experiments an effective neutralization temperature of minus 50°C was used.

The purpose of the present invention is to develop a faster and more effective method for neutralizing freeze-resistant Trichinella larvae in the carcasses of commercial fur-bearing animals without additional technological processing of raw meat (cutting, grinding into minced meat). The secondary objective of the invention was to develop a safe method of feeding raw meat that would stop the spread of trichinosis with animal carcasses, and due to this, sanitary and hygienic conditions were gradually improved and some environmental issues were resolved in nurseries, hunting grounds and in specially protected areas. Trichinosis would also be prevented in domestic animals, in particular in hunting, guard, and service dogs.

The proposed method of neutralizing meat products for the prevention of trichinosis in game animals by deep freezing trichinella-infested animals used for food is simple in execution, technically feasible both in veterinary and sanitary examination laboratories, and in the feed kitchens of animal farms or at home, where there are low-temperature freezers or freezers. The method does not require special training of operating personnel, since freezers are used for their intended purpose (deep freezing of carcasses), but only requires maintaining the proposed specified technological parameters - freezing time, weight of processed meat products.

The effectiveness of the proposed method for neutralizing Trichinella larvae in the carcasses of some fur-bearing animals is reflected in the following examples.

Example 1. Resistance to low temperatures of Trichinella larvae in the muscle tissue of the common fox. When studying the resistance to low temperatures of Trichinella larvae isolated from a common fox shot in the Ryazan region, it turned out that they remained viable and invasive for a long time. The fox carcass was divided into samples 2-5 cm thick and weighing no more than 15 g, which were placed in freezers at minus 16°C and 23°C. Samples were examined after 8, 19, 42, 78, 107, 134, 157 and 192 days of continuous freezing at these temperature conditions.

During the study, it was found that when muscle samples from the common fox were frozen at minus 16°C for 107 days, the number of viable Trichinella larvae decreased from 96% at the beginning of the experiment to 80%, and at minus 23°C to 65%. During this period, Trichinella larvae remained invasive, which was confirmed by the results of a bioassay on white mice.

However, the invasiveness of Trichinella larvae after freezing for mice - bioassays at the same dose of infection with viable larvae (10 Trichinella larvae per 1 g of animal weight) decreased: at minus 16°C the intensity of invasion of white mice decreased to 67 larvae per 1 g of animal weight, and at minus 23°C up to 43 larvae per 1 g of weight.

The viability of Trichinella larvae remained throughout the entire freezing period - 192 days at minus 16°C and 134 days at minus 23°C. The experiment was terminated due to the lack of sufficient muscle tissue samples from the fox. The high frost resistance of Trichinella larvae in the muscle tissue of the common fox characterizes their belonging to a helminth species resistant to negative temperatures.

Example 2. Experience in neutralizing carcasses of fur-bearing commercial animals naturally infested with capsular trichinella. The infested trichinosis material consisted of carcasses without skins of various types of game animals caught on hunting grounds (foxes, raccoon dogs, martens). The presence of invasion and the degree of invasion of the material were determined by compressor trichinoscopy. To do this, from each muscle sample weighing about 50 g, 24 sections of muscle the size of an oat grain (with a total weight of about 0.7-1.0 g) were cut along the muscle fibers using curved scissors. The sections were compressed between compressor glasses and microscoped at low microscope magnification. The intensity of invasion was determined by counting Trichinella larvae in 1 g of muscle tissue. During the production test for neutralization, carcasses of infested animals were isolated from uninfected carcasses, packaged separately from each other and tied in plastic bags with a volume of up to 30-200 liters.

Bags with carcasses of animals infected with Trichinella larvae were placed in the freezer compartment, which was previously turned on before neutralization (8 hours before the start of work). The invasive material was kept in the freezer for a certain time depending on the type and weight of the animal carcass (Table).

To neutralize the invasive material, it should be placed in the freezer gradually. From 30 g to 20 kg were placed in an empty freezer with a volume of 2 5 m 3. In this case, the invasive material was filled gradually, adding 10 kg portions every 4 hours of operation of the freezer, but not more often.

Quality control of the neutralization of invasive material in the muscle tissue of animals after thawing of carcasses for the viability and invasiveness of the larvae of the causative agent of trichinosis was carried out according to the method for determining the viability and invasiveness of Trichinella larvae. When the larvae were isolated by digestion in artificial gastric juice, it turned out that the isolated larvae were non-viable.

Table
Neutralization of game animal carcasses from Trichinella larvae during deep freezing
Type of animal carcasses (Latin name)	Carcass weight, kg	Decontamination temperature, °C	Exposure time, h
1	2	3	4
Common fox (Vulpes vulpes)	3,5-8,0	minus 70	18
Raccoon dog (Nyctereutes procyonoides)	2,5-9,0		18
Stone marten, forest marten (Martes foina, martes)	0,4-1,8		6
Gray rat (Ratus norvegicus)	up to 0.5		5
White laboratory rat Vistar (Rat white)	up to 0.5		5
White laboratory mouse (Mouse white)	up to 0.035		1

Example 3. Conducting a biological test on laboratory animals after neutralizing Trichinella larvae by deep freezing. After neutralization by deep freezing at minus 70°C of carcasses of commercial animals naturally infested with capsular larvae of Trichinella (fox and raccoon dog for 18 hours, martens - 6, rats - 5, mice - 1) from the causative agent of trichinosis, a biological test was carried out on laboratory animals (white mongrel mice). Trichinosis animal carcasses frozen at minus 23°C for the same period of time as in the experimental group and carcasses not subject to freezing served as controls. The muscle tissue of the animals was dissected from the bones and ground in a meat grinder. The finished minced meat was placed in mill gas (mesh size 1 mm). Then the mill gas with minced meat was placed in freshly prepared gastric juice (per 1 liter of distilled water: 10 ml of concentrated hydrochloric acid and 3 g of pepsin 100,000 units of activity). The ratio of minced meat and gastric juice should be 1:20. Minced meat prepared for artificial digestion in gastric juice was placed in a thermostat at 37°C for 18 hours. After exposure, the sediment was washed three times in distilled water. An isolated suspension of Trichinella larvae after artificial fermentation from each group of animals was administered at a dose of 5 larvae per 1 g of white outbred mouse weight. Next, laboratory mice of each group were kept according to generally accepted sanitary and veterinary rules. After 45 days, the laboratory animals were euthanized using medicinal ether in a crystallizer with a ground-in lid. To diagnose trichinosis in mice, compressor trichinoscopy was performed. In the experimental group of laboratory animals, Trichinella larvae did not develop in the muscle tissue; in both control groups of white mice, capsular Trichinella larvae were registered.

The proposed method, which includes the use of freezers with a significantly low cooling temperature, ensures rapid and effective neutralization of Trichinella larvae in muscle tissue.

Information sources

1. Bessonov A.S. Epizootology (epidemiology) and prevention of trichinosis. Mintos, Vilnius, 1972. - 304 p.

3. Veterinary legislation. - M., 1988. - T.IV. - 162 s.

5. Trichinosis. Scientific works of VASKHNIL, Moscow “Kolos”, 1976, 338 p.

Update: October 2018

The causative agent of trichinosis

How can you get infected?

The mechanism of infection with trichinosis is nutritional, and the route of transmission is oral, through meat infected with trichinosis. The disease is a natural focal disease, although foci of infection can be not only natural, but also synanthropic.

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

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, dogs).

Prevalence of trichinosis

Natural foci of helminthiasis have been recorded since North America, Germany and Poland, Ukraine and Belarus, as well as 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 human susceptibility to trichinosis;
• group outbreaks - collective consumption of contaminated meat;
• unstable immunity, which provokes repeated cases of infection after the initial infection.

Phases of development of helminthiasis

The development of helminthiasis occurs in several stages:

• Enzymatic-toxic

The initial phase of the disease takes 7–14 days after infection. Infective larvae enter the intestinal mucosa, where they develop into adult Trichinella, which during their life processes form enzymes and metabolites, which causes intestinal inflammation.

• Allergic

• Immunopathological

Develops by 5–6 weeks after invasion. Systemic vasculitis and associated severe organ damage occur. Complications of trichinosis such as meningoencephalitis, myocarditis, focal pneumonia and others appear.

Classification

Depending on the severity, the disease occurs in mild, moderate and severe forms. Typical and atypical forms of helminthiasis are also distinguished. Atypical include erased and asymptomatic trichinosis. There are acute and chronic trichinosis.

Clinical picture

Manifestations of mild and moderate forms

The disease includes 2 periods:

• acute (allergic reactions and damage to internal organs);
• recovery period.

The tetrad of symptoms of trichinosis in humans includes:

• fever;
• edema syndrome;
• pain syndrome (in muscles);
• high level of eosinophils in the blood.

Clinical manifestations:

• Fever

The temperature rises to 40 degrees for several days, then sharply decreases to 37, which lasts 7 - 10 days. In some cases, low-grade fever persists for several months. A mild course of the disease may not be accompanied by hyperthermia. Against the background of high temperature, signs of general intoxication appear: weakness, chills, sweating and nausea, headache.

• Facial swelling

A characteristic sign of helminthiasis is the appearance of swelling of the eyelids and face as a whole, which is often combined with conjunctivitis. As a result, trichinosis is also called “puffiness.” Swelling occurs on the 1st 05th day of the disease and persists for up to two weeks. In cases of severe disease, swelling appears more slowly, but lasts longer. The sequence of appearance of edema: eyelids, brow ridges, entire face. In severe cases, swelling reaches the neck, torso, arms and legs, which is considered an unfavorable prognostic sign.

• Myalgia

Starting from the third day of illness, sometimes later, muscle pain occurs in various muscle groups. First of all, myalgia appears in the muscles of the legs (calf muscles), then spreads to the gluteal muscles, muscles of the back and abdomen, covers the arms and shoulder girdle, rises to the cervical and pharyngeal muscles, muscles of the tongue, chewing and oculomotor muscles. Such pain is very pronounced, intensifies with movement, and palpation of the muscles causes pain. In severe cases, myalgia with contractures develops, which leads to immobilization of the patient. Both myalgia and edema persist for up to 1–3 weeks and periodically recur, which is accompanied by an increase in temperature.

The acute phase of the disease is accompanied by abdominal syndrome (pain, nausea, vomiting, diarrhea) and allergic manifestations - rash (rosacea - pink blisters that turn pale when pressed, urticaria - spots merging with each other, urticarial - blisters raised above the skin).

• Eosinophilia

The level of eosinophils increases to 80%, which appears with the first symptoms of helminthiasis. The maximum increase in eosinophils is observed at 2–4 weeks of illness (mild up to 30%, moderate up to 60%). An unfavorable prognostic sign is an increase in eosinophils to 95%.

Severe course

A severe form of the disease is accompanied by the development of organ lesions that appear 3 to 4 weeks after infection. It is organ damage that often becomes the cause of death of the patient.

The following complications arise:

• allergic myocarditis is the leading cause of death of the patient (increased heart rate, decreased blood pressure, signs of acute vascular insufficiency, ECG symptoms of diffuse myocarditis);
• lung damage - the development of pneumonia in combination with pleurisy, which is caused by systemic vasculitis;
• brain damage (encephalomyelitis, encephalitis, meningitis);
• liver damage - hepatitis;
• thrombohemorrhagic syndrome (blood clotting disorder);
• kidney damage - nephritis.

The duration of the disease in the case of a mild course ranges from 7–14 days to 35–42. If treatment is started on time, the duration of each period is reduced by 3–5 days. The recovery period in case of severe helminthiasis is delayed to half a day or more. Prolonged muscle pain occurs in patients taking immunosuppressive drugs (glucocorticoids).

Symptoms depending on the stage of the disease

Infestation stage

Dissemination stage

At this stage, the functions of the affected organs are restored (15–20 days), muscle pain persists for up to 2 months, and eosinophilia for up to 3 months.

Diagnostics

Diagnosis of trichinosis is difficult, since in the early stages of the disease it is often confused with the flu, colds and allergies unknown origin. A thorough medical history plays an important role in diagnosis; the doctor should be alert to the patient’s consumption of game. At the same time, all participants in the feast are required to be examined.

Also, suspicion of trichinosis should be caused by a characteristic set of symptoms: periorbital edema, heat and muscle pain.

Laboratory research methods:

UAC

Serological diagnosis

• RNGA;
• RIF and others.

Skin allergy test

Muscle biopsy

To carry out trichinoscopy - identifying larvae in the muscles, the deltoid and gastrocnemius muscles are examined. The material is obtained by puncture of the muscle, and then studied under a microscope.

Meat check

Tests for this helminthiasis are carried out by veterinary laboratories available in markets and the laboratory of the sanitary and epidemiological station. Sampling is done from the entire carcass. Small pieces of meat (about 5 grams) are collected from the intercostal muscles, diaphragm, tongue and masticatory muscles. If at least one larva is detected, the meat is considered contaminated and destroyed. To destroy, they dig a hole at least one meter deep, douse the meat with kerosene and bury it. Or clean meat is covered with quicklime and buried.

• Mebendazole (Vermox)

• Albendazole

• Tibendazole

The effectiveness of the drug is lower due to pronounced adverse reactions. Dosage: 25 mg per kg of patient weight. The course lasts 3–5 days, the medicine is taken twice a day. If necessary, carried out re-treatment(after 7 days).

In severe cases, with the development of organ pathology, glucocorticoids are included in the treatment regimen. Glucocorticoids suppress the immune system, thereby reducing allergic manifestations.

The effectiveness of treatment is assessed after six months to a year.

In case of immobilization of the patient and the development of muscle contractures, massage, physiotherapy and special gymnastics are prescribed.

In parallel with the main treatment, the patient is prescribed hepatoprotectors and multivitamins, as well as drugs to improve microcirculation.

Question answer

Question:
Is it possible to cure trichinosis using traditional methods?

Question:
How should you cook meat suspected of helminthiasis?

Suspicious meat should be subjected to prolonged heat treatment. When cooking, cut the meat into pieces no larger than 8 cm and boil for at least 3 hours. Frying suspicious meat should be done in small pieces (up to 2.5 cm), and after frying the meat should be simmered for at least 1.5 hours. It is prohibited to use lard for salting/smoking, and use it only after heating.

Question:
Is it possible to disinfect suspicious meat by freezing?

Yes, this method is quite effective, but subject to certain conditions. Meat should be kept for 20 days at a temperature of -15 degrees or three days at a temperature of -20 degrees.

Question:
Is it possible to become infected with trichinosis by eating salted or smoked lard?