Trichinosis. Methods of infection, symptoms, diagnosis and treatment of the disease. How are meat products and meat tested for the presence of the causative agent of trichinosis? How to check meat for trichinosis and is it possible to neutralize infected game by heat treatment? Where is it checked?

In a fight with a wild boar, one person risks his life - the hunter. When a boar is dead and turned into food, the lives of everyone who ate it are at risk. The source of danger is trichinosis.

According to statistics from the Department of Infectious Diseases of the Belarusian State University of Medicine, “in the Soviet era, 80% of all cases of trichinosis occurred in Belarus. Since gaining independence, from 10 to 100 cases of disease have been registered in our country per year.”

- What are the consequences of Trichinella entering the human body?

It all depends on the moment you go to the doctor. If it is late, trichinella will reach the muscle tissue. In general, the “life path” of Trichinella is as follows: entry into the gastric tract - achievement of sexual maturity - mating of male and female Trichinella - generation of larvae - their penetration into the blood vessels - entry of Trichinella into muscle tissue.

- When do the first signs of the disease appear?

Maybe on the 3rd day, or maybe after 3 weeks.

- What are the symptoms of the disease?

It all starts with a sudden rise in temperature and diarrhea. Then follow: fever, intoxication, swelling of the eyelids, facial pastiness, conjunctivitis, skin rashes. Finally, severe pain in the masticatory and intercostal muscles. It should be repeated that internal organs and the central nervous system are affected at an advanced stage.

- Which animal meat is the most dangerous?

Trichinosis is the result of animals feeding on carrion. Therefore, it is primarily found in carnivorous and omnivorous animals: wild pig and wild boar, nutria, raccoon, badger, bear, etc.

- Can heat or other processing of meat protect against disease?

Only a laboratory will give a 100% guarantee. There is an opinion that “if laboratory control is not possible (camping trip, hunting far from civilization, etc.), you should boil the meat for 2.5 - 3 hours. The thickness of the pieces of meat should not exceed 2.5 cm". This is not true. Trichinella “goes” into the broth and remains in the meat.

Long-term storage of canned pork, sausages, etc. also ineffective - smoking, drying and salting do not destroy Trichinella. Under no circumstances should you try raw minced meat on your tongue.

- Where can I check the meat? How much will it cost?

The test is carried out using the compressor trichinoscopy method and costs Br5810. There are laboratories at large food markets. A more accurate analysis - by digestion in gastric juice - will cost Br7500. It will be placed in the laboratory at the address: st. Gursky, 42.

- What does “more accurate analysis” mean?

- The “digestion research method” imitates the work of the human stomach. The meat being tested is twisted in a meat grinder, then placed in artificial gastric juice at human body temperature for 1.5 hours.

There are cases when the microscope did not detect Trichinella. But after checking them using the “digestion” method, darkness was discovered.

- How much meat should be sent for analysis?

For research, you do not need to take the entire carcass to the laboratory; 120 g of meat is enough. Ideally, this is the intercostal diaphragm - the hymen that separates the animal's intestines from the chest. This is where Trichinella manifests itself first.

- When is meat rejected?

If at least one larva is found, the entire carcass must be disposed of.

- When was the last outbreak of this insidious infectious disease recorded?

This winter, a student from Vitebsk, returning from vacation, brought wild boar meat to Minsk. The hostel threw a feast on this occasion.

The next semester, 13 people were met at the hospital.

We noticed that articles on cooking wild boar and even bear are especially popular on our website:

Of course, every hunter who has caught a boar while hunting is proud of it and is happy to cook at home from wild boar meat. However, failure to follow certain rules can lead to trichinosis. Trichinella larvae can be found in the meat of pigs, wild boars, bears, badgers and other carnivores. Therefore, on the eve of the opening of the spring bear hunt and taking into account the fact that in some regions the shooting of wild boar continues in connection with ASF, we remind you of precautions!

What is trichinosis?

The first symptoms of trichinosis:

• muscle pain,
• swelling,
• fever,
• muscle weakness.

According to statistics, periodically occurring group diseases of this invasion were mainly associated with the consumption of wild boar meat in the form of kebabs, home-made dry-cured sausage, ham, fried meat and cutlets, and sandwiches made from raw minced pork. In all these cases, no veterinary examination of the carcasses was carried out.

For hunting enthusiasts, we should remind you that post-mortem veterinary examination of wild boars is mandatory for your health and the health of your loved ones! Veterinary examination of domestic pigs and wild boars is carried out by specialists from the veterinary service of meat processing plants, meat processing plants, markets, city and regional veterinary institutions.

Four residents of a Kamchatka village became infected with trichinosis after eating bear meat

In March of this year, cases of trichinosis infection have already been registered. And this happens every year. It is especially tragic when not only careless adults become infected, but also, despite warnings, give untested wild animal meat to children.

The fight against trichinosis is carried out comprehensively: by medical, veterinary and game management organizations with mandatory mutual information between them.

The larvae settle in the muscle fiber of an infected person and partially destroy it. After about a month, a dense fibrous capsule forms around each larva (and their number can reach 15,000 per 1 kg of muscle), which thickens over time due to calcium salts. In this state, the larvae can remain alive for many years.

Within a day or two after the invasion, a person exhibits the following symptoms:

• diarrhea;
• heartburn;
• nausea;
• dyspepsia (difficulty in digestion).

• muscle/joint pain;
• swelling;
• chills;
• migraine;
• cough.

In the most unfavorable development of the disease, Trichinella penetrates the brain, which causes paralysis or ataxia of the respiratory tract and subsequent death. Also, death is possible due to developing encephalitis, allergic myocarditis and pneumonia. Death can occur in just 4-6 weeks after infection - faster than with any other helminthiasis, so it is extremely important to immediately take a blood test for trichinosis if similar symptoms appear after eating meat.

If the hunter or farmer has the opportunity, it is advisable to send animal meat for a professional laboratory test for trichinosis. There are several reasons for this:

• veterinary experts have extensive experience in detecting representatives of all types of Trichinella, including non-encapsulated T. pseudospiralis, T. papuae and T. zimbabwensis, which can easily be missed by an amateur;
• laboratories use expensive microscopes, much more accurate than portable trichinelloscopes;
• The tests themselves are also more detailed - sections are taken not only on the diaphragm, but also on the intercostal, calf, masticatory and tongue muscles, and pieces of meat are dissolved in artificial gastric juice.

Similar laboratories are equipped in any major city. For example, in Moscow you can submit meat for analysis at the State Veterinary Clinic at ul. Yunatov, 16A.

Experienced hunters claim that a dead boar is more dangerous than a living one. After all, his body can be a haven for trichinella. These roundworms cause a dangerous disease in humans when they eat wild animal meat.

Infection can be prevented by cooking the prey for several hours. And even better - pre-check the meat for the presence of helminths. This can be done at a state veterinary clinic or in a laboratory at a food market. But there are situations when the question is how to test boar meat for trichinosis at home.

Trichinosis develops due to the fact that the animal feeds on carrion. It mainly affects carnivores and omnivores.

The source of the pathogen is pigs, wild boars, badgers, raccoons, bears, walruses, and seals. Most often, infection occurs by eating meat with Trichinella larvae. Fat with muscle layers is also dangerous.

The life cycle of Trichinella can be briefly summarized as follows:

• The larvae enter the gastrointestinal tract after eating contaminated meat.
• There they reach sexual maturity.
• Males and females mate.
• New larvae appear (Trichinella does not even need to lay eggs - it is viviparous).
• They penetrate the circulatory system.
• From there, Trichinella spreads into muscle tissue.

In some cases, the disease becomes obvious already on the 3rd day after eating meat, although this period sometimes extends to 3 weeks. First, a patient with trichinosis complains of loose stools and a fever. Then a fever begins, the eyelids swell, and skin rashes appear. This is followed by severe pain in the area of ​​the masticatory and intercostal muscles. The advanced stage is characterized by damage to internal organs and the central nervous system.

How to protect yourself from trichinosis

According to gamekeepers, this disease affects most animals older than 4–5 years. Therefore, it would be useful to take measures to protect against trichinosis if you cannot refuse the meat of forest inhabitants. Why rely on chance if the consequences can be very sad? Therefore, it is wise to refrain from buying wild meat secondhand. It is unlikely that anyone can guarantee that it does not contain Trichinella. It is unlikely that poachers will take their catch for inspection, because the laboratory will require a license and a veterinary certificate.

Laboratory assistants use 2 methods - compressor trichinoscopy and digestion (imitation of the work of the human stomach).

How to check meat yourself

You can become infected with trichinosis from 120 species of wild animals and some birds. The danger comes even from hares and horses. Nematodes are also found in domestic pigs, which are released for pasture and not kept constantly in a stall. Thus, testing meat for trichinosis is required in many cases.

There are situations when laboratory testing is not available. For example, you find yourself on a hike far from civilization. Or you were unable to find a laboratory where they test meat for trichinosis. This issue cannot be resolved using improvised means; you will need a special tool. The portable trichinelloscope is similar to the equipment used in professional laboratories. The device is highly effective, but for many, its price will be a serious drawback - from 11,000 rubles.

Among users of hunting forums you can find tips and recommendations on how to adapt a school microscope to check meat for trichinosis. Craftsmen even assemble the devices themselves, using drawings from magazines like Young Technician.

If you decide to test your meat yourself, you should understand that maximum protection is not guaranteed. When using a portable device, you can easily make mistakes. The procedure is distinguished by its subtleties. And the analysis itself is not so simple.

What is a check?

For research you will need the following materials:

• Sections of the muscle of the legs of the diaphragm are those areas where it is attached to the spine.
• Sections of masticatory, intercostal, gastrocnemius, and extraocular muscles.
• Tongue cut.

We need pieces from the places where the muscles turn into tendons. The size of the cut (there should be 72 if the animal is wild, and 24 if it is domestic) is no larger than an oat grain. Each of them is placed on a glass slide, covered with another and crushed. Thus, a typical check involves hundreds of views of individual slices.

The study aims to detect round or oval capsules in meat. A distinctive feature is that triangular-shaped fatty deposits are visible on their periphery. You can see the larva inside the capsule. The following points must be taken into account:

Without knowledge and experience, trichinella in meat can be confused with air bubbles or echinococcus finns, sarcocysts, and calculi.

What to do with contaminated meat?

For humans, a lethal dose is considered to be 5 larvae per 1 kg of body weight. In a sick animal, the muscle tissue is strewn with tens of thousands of Trichinella. To become infected, 30–50 g of such meat will be enough.

If you decide to take a risk, then get ready to cook the carcass for at least 4 hours, after cutting it into small pieces. It is believed that Trichinella dies at 80 degrees. Frying, stewing, or cooking over coals will not provide such a temperature. Meat with trichinosis cannot be used to make raw smoked delicacies, whites, dumplings, ham, and lard.

Having become the owner of a bear, wild boar or badger carcass, do not rush to rejoice and rush to grill kebabs. First check such meat for the presence of Trichinella. Don't take risks with at-home methods, including using special equipment. The most reasonable decision to protect yourself and your loved ones is to take the meat to the laboratory to be tested for trichinosis. Specialists have the tools, experience, and knowledge that allow them to accurately determine whether it is infected.

- a parasitic human disease that is caused by very small nematode worms. Infection most often occurs through consumption of contaminated meat that has been poorly cooked. Since trichinosis mainly affects wild animals, hunters and other people who eat game are at greatest risk. It is very important to know how to test meat in order to avoid contamination.

Larva in meat

The difficulty of testing meat for trichinosis is that the worms are very small. Males can reach several millimeters, females - a little more than a centimeter (although larger individuals are sometimes found). Unlike roundworms, etc., it is very difficult to visually notice trichinella in meat. Therefore, cases of infection are quite widespread.

Forms of flow

Trichinella

Depending on the characteristics of the body, the patient may have both types of progression, or only one of them.

Infected animals

Any meat can be contaminated, so you need to be very careful when processing it. However, Trichinella is most often found in the carcasses of the following animals:

1. Pigs;
2. Boars;
3. The Bears;
4. Hares.

All carnivorous and omnivorous animals in the wild are also susceptible to invasion - rodents (almost all species), nutria, wolves, foxes, badgers. Pets, mainly dogs, are also susceptible to infection. Therefore, they should not be consumed with raw meat that has not been tested for trichinosis at home.

Poultry meat also potentially poses a risk for this disease, since scientists recently discovered another causative agent of trichinosis that affects birds. It is transmitted less frequently to humans and animals, but can still infect them.

Signs of contaminated meat

Anyone who eats meat from animals killed during hunting needs to know how to test meat for trichinosis. There are several rules for conducting such a check:

1. Each carcass that will be eaten is checked;
2. If there is a lot of meat and it is consumed regularly, then it is better to conduct a laboratory analysis of the carcass for trichinosis;
3. If signs of infestation are detected, the meat should not be eaten even after proper processing;
4. If at least one larva is found, then the entire carcass must be disposed of;
5. Any meat should be treated as potentially contaminated.

Both boar meat tested and untested for trichinosis must be carefully processed.

Infestation in a bear or other game can be diagnosed by the following signs that are visible in the meat:

In cases where it is not possible to take the sample to the laboratory, you have to use a special device for hunters - a portable trichineloscope. Essentially, this is a compact microscope with low magnification. This device is designed for testing meat at home. It is quite versatile and can magnify the sample up to 50 times.

Tissue areas are examined. It is mainly necessary to examine the muscles in those places where they grow together with the tendons. It is worth selectively examining other muscle tissue and some internal organs. During the inspection it is important:

In some cases, during testing it is necessary to use chemical compounds, in particular HCl. This is done in order to differentiate the larva from safe formations. If this analysis is necessary, it is better to take the meat to the laboratory.

Prevention of infection

Trichinella can remain active and infectious after prolonged freezing, as well as after prolonged cooking. The cysts that the larvae form around themselves are not destroyed either by low or high temperatures. Therefore, no matter how carefully the meat is processed, the likelihood of infection is still present. If trichinosis has not been diagnosed, then such meat, even carefully processed, should not be eaten.

Symptoms

Checking the meat is very important. Since trichinosis is a rather dangerous disease. For example, if the concentration of larvae is more than 5 pieces per 1 kg of body weight, there is reason to assume a fatal outcome. A person experiences the following symptoms at the larval stage:

1. Chills;
2. Sweating;
3. Increased body temperature;
4. Swelling of the face;
5. Allergic reactions;
6. Muscle pain;
7. Joint pain.

At the intestinal stage, other symptoms occur:

1. Diarrhea and constipation alternate;
2. Loose stools mixed with blood and mucus;
3. Stomach ache;
4. Bloating;
5. Flatulence;
6. Changes in taste preferences;
7. Weight loss;
8. Loss of appetite;
9. Nausea.

In people at risk, if such symptoms are detected, treatment should be started immediately. Since the development of invasion in the body can occur quite quickly.

Treatment

You can learn more about trichinosis from the video.

Video

Many people think that the warning from experts that a dead wild boar or beaver can be more dangerous than a living one seems, at least, funny. Meanwhile, this is true: during a fight, a living animal can injure only one, or at most several people, but a dead one can infect a large number of those who taste dishes prepared from its meat with trichinosis. What kind of disease is this and what are the risks of contracting it?

Features of the disease

Trichinosis is an acute helminthiasis that affects mammals. It is also dangerous for humans. Differs in severe clinical manifestations. It is not uncommon for a person to become unable to work after suffering from an illness. But the worst thing is that infection with trichinosis can cost a person his life.

The cause of this disease is Trichinella. These are very small worms, almost thread-like, photos of which can be seen on the Internet if desired. Adults can be from one and a half to 1.8 millimeters in length, with a width of only about 0.05 mm.

Soon after the larvae enter the human body and the bloodstream spreads them throughout the body, a person may experience:

1. Muscle pain.
2. High eosinophilia.
3. Fever.
4. Skin rashes.
5. Swelling of the face.

1. Lungs.
2. Myocardium.

Today, trichinosis is treatable, but just 100 years ago, entire families died from it. After all, the meat of an infected animal, for example a wild boar, does not differ from the carcasses of healthy animals either in appearance, smell, or color. But just one gram of it can contain up to 200 larvae.

Analysis

Impressive, isn't it? But it’s very easy to avoid all the troubles that trichinosis can cause: you need to check the animal’s meat for the presence of helminths. Moreover, it is necessary to check the material from both wild animals and domestic ones: data on contamination indicate that trichinosis larvae were found both in samples of badgers, beavers, bears, wild boars, wild birds, and horses, domestic pigs, and chickens submitted for analysis.

But in order to conduct a study, it is necessary to provide the taken material to a laboratory (this can be a sanitary and epidemiological station or a veterinary laboratory, which is available in every market). Moreover, the entire carcass must be provided for inspection, since sampling for inspection is carried out in different parts of it. These are the parts where blood circulation is best developed. These include:

1. Chewing muscles.
2. Language.
3. Diaphragm.
4. Intercostal muscles.

Why are these particular places on the animal carcass so important for research? Because if an animal is infected, these are the areas where most of the larvae are located, where they are carried into the bloodstream.

For examination, pieces weighing about 60 grams are cut off. Next, sections are separated from each sample. their size does not exceed the size of an oat grain. For example, meat for testing from a wild animal is divided into 72 sections. The material in domestic animals is divided into 24 sections. Then the selected slice is placed on the glass of the compressorium. The top is covered with another glass. After this, the material is crushed using special screws. Now all that remains is to examine the sample under a trichinelloscope or a special microscope.

But such a procedure is not only very complicated, but also not always possible - it is often a long way to get to the laboratory. In addition, you will need to explain where the meat was taken, whether there are documents for shooting the animal, if it is game, in general - nothing but problems. Therefore, most people eat barbecue at their own risk, stew meat on a fire right in the forest after a hunt, or at home, hoping that it will carry through. What you will have to pay for such frivolity is described above.

Home analysis

But what should those who cannot deliver the carcass of an animal killed during a hunt for laboratory testing do? And the point is not at all that I didn’t want to carry it - there are times when it is impossible to do this. For example, hunters spend months on the land while harvesting fur-bearing animals and are sometimes separated from civilization by several hundred kilometers. They consume meat from hunted animals without inspection.

There is a solution for such cases: you can purchase a special device - a compact microscope. It's called a portable trichinelloscope. Below are its main characteristics:

1. One battery of this device can operate for 60-65 hours.
2. Weight with packaging – 0.7 kg.
3. The dimensions of the device are 24.0x7.3 cm.
4. Service life – 3 years.
5. The temperature at which the device can operate is from +50 to – 20 degrees.
6. There are quite powerful devices, the magnification factor of which is 50, but if you wish, you can buy a trichinelloscope, the power of which is 200.

Thanks to this, rapid analysis of meat can be carried out at home or in the field - it all depends on whether it was hunting or slaughtering, for example, a pig at home.

Of course, the cost of such a device is not very small. But if you consider that its presence will help maintain health (and, sometimes, life), then such a price is not so high. In addition, several people can purchase a compact microscope, for example, neighbors or those who go hunting together. Then the cost of the device will be affordable to almost anyone.

What should you look for when self-testing for trichinosis using this device? The capsules must be found. They can be oval or round in shape. There should be triangular-shaped fat deposits on their periphery. There is usually a larva inside. Using a 1% methylene blue solution can improve the ability to view the larvae. If there is very little limestone on the capsule, 5% hydrochloric acid should be added to the cut. Just two or three drops are enough to determine whether the material is contaminated.

In addition, when doing analysis at home, you need to be very careful not to confuse the capsules of trichinosis larvae with:

1. Air bubbles. The larvae vary in size. In addition, they have a well-defined black border.
2. Concretions. They differ in shape and size. It is necessary to clarify the obtained data after using NS1.
3. Sarcocysts, which are distinguished by the internal structure of a mesh-like appearance and elongated shape.
4. Immature Finns. They are oval shaped and larger.

To avoid mistakes, one microscope device is not enough - you definitely need to know the “enemy in person”, that is, study well the photos on the Internet depicting helminths of this species. Moreover, you need to pay attention to those where the larvae are removed from the meat in order to have an idea of ​​what it looks like in life.

In laboratories, artificial gastric juice is sometimes used for analysis. The muscles dissolve in it. You can carry out such a check on the meat of an animal, for example, a beaver, if you purchase this material in advance and take it with you on a hunt.

If during the analysis it was possible to find only one larva, the entire carcass will have to be disposed of. Moreover, with the head and esophagus. In this case, experts recommend using only internal fat and internal organs for food.

Thus, examining the carcass of a hunted or slaughtered domestic animal is not something simple. And if you consider that the lives of those who will cook and eat meat products depend on the quality of the inspection, then it is better to entrust this matter to professionals, although this does not give a 100% guarantee: there have been cases when, even after tasting fresh meat that has passed the inspection, wild boar, bear, beaver, people became infected with trichinosis larvae. This is because it is very difficult to detect Trichinella, especially in the initial stages, even using the most modern equipment. Taking this into account, it is necessary to cook the meat, subjecting it to high-quality heat treatment and not eating it half-raw, so experts do not recommend cooking rare steak.

In addition, in order to avoid infection with trichinosis, in order to preserve health and nerves, it is not advisable to purchase raw meat products at spontaneous markets: even the documents provided there are not a guarantee of the quality of the inspection and do not indicate that the certificate was received for the carcass that is in sale.