Trichinellosis (trichinellosis) is a helminthiasis.
Pathogen trichinosis - round helminth Trichinella (Trichina) - Trichinella spiralis. The length of the male is 1.5 mm, the female 3-4 mm. At the puberty stage, Trichinella parasites in the mucosa of the small intestine. Females excrete larvae that penetrate into the lymphatic and blood vessels and settle in the striated muscle, where they are encapsulated (Fig.). In the intestines of Trichinella, after 10-84 days, they die; larvae in the musculature can live up to two years or more.
Encapsulated larva of Trichinella in muscle.
Epidemiology . Trichinosis is a natural focal disease of a person, domestic animals (pigs, dogs, cats) and wild animals (bears, wolves, badgers, foxes, wild boars, etc.), as well as synanthropic rodents (rats, mice). Infection with human trichinosis occurs when eating meat pigs and often meat of wild animals (bear, badger, wild boar, etc.). Pigs are infected with trichinosis by eating corpses of dogs, cats, rats, carcasses of fur-bearing animals, abandoned by hunters after removing their skins from them, while feeding them with waste from slaughterhouses.The
Circulation trichinella invasion in nature is carried out in the process of predation and eating of carrion. Wild animals (wolves, etc.) can become infected with trichinosis and within populated areas, attacking domestic animals (dogs, etc.) and eating their corpses on poorly contained cattle cemeteries .
Pathogenesis . The main in the pathogenesis of trichinosis is the sensitization of the human body by metabolic products and the decay of trichinella with the subsequent development of allergy (see).
Clinical picture (signs and symptoms). The incubation period is 3-45, usually 10-20 days. The main symptoms of trichinosis - eyelid swelling, puffiness of the face, fever, pain in the muscles, sometimes there are swelling on the legs and hands; is characterized by eosinophilia of the blood. After 1 -3 days after the appearance of the edema of the eyelids, the temperature rises. There are pains in the musculature of the eyeballs, limbs, trunk, in the tongue. Sometimes contractures of the knee and elbow joints develop, a trisus of masticatory muscles appears. Often there is a polymorphous skin rash. Sometimes there are gastrointestinal disorders. Headache, insomnia or, conversely, drowsiness are often noted. Eosinophilia of blood reaches 80% and is often accompanied by leukocytosis; in especially severe cases, eosinophilia is sometimes absent. Sometimes trichinosis is atypical with the phenomena of meningitis, encephalitis . Relapses of the disease are possible.
The diagnosis is based on the clinical picture of the disease and the results of a microscopic examination (trichinoscopy) of pieces of muscle taken from a biopsy.
Treatment . From the means of pathogenetic antiallergic therapy hormonal preparations are used. Assign on the day 40 mg prednisolone , or 2-4 mg dexamethasone, or 60-80 ED adrenocorticotropic hormone (ACTH). When the patient's condition improves after 2-3 days, the daily dose is reduced by 1/3 and the treatment is continued for 5-7 days. From the second week the dose of the drug is gradually reduced to the level of "maintenance" (5 mg of prednisolone, 0.25 mg of dexamethasone, 5-10 units of ACTH per day); in this dose the drug is prescribed for 1-2 weeks. With hormonal therapy, potassium salts are prescribed up to 3-4 g per day; in food, sodium salts are limited. In the case of a mild course of the disease, butadione, acetylsalicylic acid, dimedrol is used.
Prevention . Carcases of pigs and wild animals used for human nutrition, as well as animal animals are subject to veterinary and sanitary inspection with mandatory trichinelloscopy. All trichinosis carcasses are subjected to technical disposal. If it is impossible to conduct trichinelloscopy (in expeditions), wild animals are cooked for at least 2.5 hours with pieces of not more than 2.5 cm in thickness. House rodents are destroyed. In case of impossibility of technical utilization, animal carcasses are doused with kerosene and buried deeply on cattle graves.