Trichinosis of pigs: symptoms and diagnosis, methods of treatment and prevention

Trichinosis is an invasive disease of many animals and humans. It is caused by trichinella - round small nematode worms that parasitize only inside the host organism. Trichinosis of domestic pigs is especially dangerous. If sanitary standards are neglected during the slaughter of animals, the processing of their meat, parasite larvae can enter the human body. Trichinosis is dangerous because there are still no reliable treatments for farm animals.

How the parasite develops

The development of the pathogen occurs inside the body in several stages.

Intestinal phase

The parasite enters the stomach of a pig or other animal in the form of live encapsulated larvae along with meat food. There, the capsules are destroyed by gastric juice, the larvae end up in the duodenum. There they are delayed for 30-40 hours. During this time, they form into adults capable of reproduction. Fertilization takes place. Males die after him.

Fertilized females with the head end are introduced between the tubular outgrowths and villi of the intestinal epithelium. The cycle of development from the egg to the larva occurs within it within 7 days. A week later, the females give birth to live larvae. After that, the next phase of development begins.

One individual can produce about 2000 larvae. Trichinella, which have laid larvae, remain alive for up to 8 weeks, after which they die and are excreted along with feces.

Migration phase

Migration routes of larvae are still the subject of scientific dispute.It is believed that they first enter the lymph. From it, the pathogen migrates to the lymph nodes, of which - to the vena cava. Further, with the bloodstream, they are carried throughout the body of the pig. The size of migratory larvae does not exceed 110 microns in length and 5-6 microns in diameter. Their movement continues until they enter the skeletal muscle tissue.

Muscle Phase

Inside the striated muscle, the larvae get under the cell walls. The muscle larva has the following dimensions:

• males are 1.1 mm long and 0.06 mm in diameter;
• females are 1.3 mm long and 0.06 mm in diameter.

Major organs are formed in the larvae during the muscular stage. They increase significantly in size. The length of females is 3-4, and males - 2.2 millimeters. The larvae curl into a spiral, and a capsule appears around them.Her education takes from 3 to 9 weeks. Another 16 months will be required for calcification. In skeletal muscle, encapsulated larvae can remain alive for up to 25 years. In the external environment, this period is half a year.

Trichinosis symptoms

In case of accidental infection of pigs, the clinical picture is erased. In about 30% of cases, symptoms are not expressed. With intensive intentional infection in animals, damage to the intestines and blood vessels is observed. The disease is characterized by the following symptoms:

• refusing food;
• sluggish behavior;
• weight loss;
• exhaustion;
• convulsions;
• puffiness;
• vomit;
• diarrhea;
• breathing disorder;
• allergic manifestations in the form of a rash.

During life, a disease in a domestic pig can be diagnosed by a combination of symptoms, analysis of tissues taken from the auricles, or through a special enzyme immunoassay. Wild boar meat is most often subjected to post-mortem examination.

Rules for diagnosing a disease

To confirm the well-being of swine herds, vital diagnostics of animals is of great importance. ELISA is of great importance in this regard. This is a special enzyme immunoassay. It is carried out in animals of any age, starting from the full 3 months of life, 3-4 weeks after infection. Identified sick individuals are excluded from the fattening group. The disadvantage of such a study is 92-97% accuracy. Therefore, ELISA does not preclude further examination of pig carcasses. To confirm the results and more accurate diagnosis, a veterinary examination is carried out in several ways. To do this, use:

1. Compressor trichinoscopy, for which 24 cuts are made from muscle tissue, crushed, and then studied under a trichinoscope or under a microscope.
2. Digestion of muscles in artificial gastric juice. Very accurate method of post-mortem diagnosis. The selected meat is ground, poured with a mixture of water, hydrochloric acid, pepsin. Put in a thermostat for 5 hours. After that, the liquid is drained, the sediment is examined.
3. Post-mortem diagnosis is carried out with a complete opening of the intestine. Adult parasites are most often found in the small intestine. A section of the intestine is cut and, together with the contents, is poured with water. After several washes, examine the sediment under a microscope.

These methods make it possible to detect Trichinella in raw meat carcasses, ready-to-eat meat products. Currently, IGF is becoming popular - enzyme immunoassay, which is carried out on special polymer membranes.

Treatment methods for swine trichinosis

Modern veterinary pharmacology has not developed effective drugs that can treat pigs for trichinosis. The following medications are allowed:

• Thiabendazole;
• Mebendazole;
• Albendazole;
• Parbendazole.

These remedies are effective only against adults, larvae up to the stage of capsule formation. There is information about the treatment with cadmium oxide, chlorophos. In most cases, animals infected with trichinella are euthanized. The carcasses are being disposed of.

Why are parasites dangerous?

Trichinella larvae, enclosed in capsules, are dangerous because they are resistant to high, low temperatures, and other destructive processes. When cooking a piece of meat weighing about 1 kg, it is possible to achieve the destruction of the larvae only after two and a half hours. The freezing process at -25 degrees should be carried out for at least 4-5 days. In rotting remains, the larvae remain alive for 4-6 months.

Parasites are very dangerous for humans.Poorly cooked, undercooked meat from infected pigs can become a source of infection for him. Complete recovery from trichinosis can occur after 6-12 months of complex therapy. In severe cases, it can cause various serious disorders in the work of the heart, the central nervous system, which causes the death of the patient.

Prevention measures

For the prevention of trichinosis, it is necessary to protect the places where pigs are kept from the penetration of rodents. Rats and mice are carriers of this disease. Strong walls, floors, lack of holes in them will become an obstacle for them.

Carcasses of animals obtained during hunting, it is desirable to bury to a depth of at least a meter, in places inaccessible for tearing by pigs, dogs, and other animals. Do not feed raw remains from the slaughter of domestic animals, fur-bearing animals to pigs. Comply with the rules for slaughtering livestock in personal and farm households. To prevent human infection, do not purchase pork that has not passed a veterinary examination.The meat obtained during the hunt must be delivered for testing to the nearest laboratory. It is important to remember that any disease is easier to prevent than to cure.

Recommended