Trichinosis in children: causes, symptoms, diagnosis, treatment

Trichinosis is an acute-febrile illness caused by a round worm - trichinella. It is accompanied by muscular pains, edema of the face, various rashes on the skin, hypereosinophilia of the blood, in case of severe myocarditis, focal lesions of the lungs, meningoencephalitis.

ICD-10 code

Q75. Trichinosis.

Epidemiology

Trichinosis is widespread. The main endemic foci of trichinosis are Belarus, the North Caucasus, Lithuania, and Georgia. In recent years, the endemic foci of trichinosis in the central regions of Russia and Ukraine began to recover, which is associated with the development of individual pig production. In Belarus, in the Northern Caucasus, in Lithuania, foci have a mixed synanthropic (naturally) -endemic character with a constant exchange of infestation between domestic and wild animals. In endemic centers, pigs are the main source of infestation, wild boars, bears, badgers in nature. In the north, there is a circulation of invasion between polar bears, polar foxes, rodents and marine mammals.

Outbreaks of trichinosis are attributable to the use of invasive, insufficiently thermally processed meat, corned beef, sausages that have not undergone sanitary and veterinary control. With non-simultaneous and uneven use of invasive meat, an outbreak or group illness can be stretched up to a month, sometimes more. Invasive products are often transported to different parts of the country. With massive infection, the first to fall ill are children.

Causes of trichinosis

The causative agent is the nematode Trichinella spiralis. Three pathogenic variants of the helminth are described: T. Spiralis, T. Nelsoni and T. Nativa. The species independence of the options has not been finally established.

Sexually mature female Trichinella up to 1-3 mm long, male 1-2 mm long. Parasites are located in the mucosa of the small intestine, partially hanging in its lumen. After fertilization of females males die. Fertilized females begin laying larvae in 2-3 days, which penetrate into the blood and lymph vessels of the intestinal mucosa and through the portal vein system and the thoracic duct enter the blood and lymphatic drainage. Partly lingering in the parenchyma of internal organs, they settle in the striated muscle. Depending on the intensity of infestation, females are in the intestine and produce larvae for 3-6 weeks. In skeletal muscles for 3-4 weeks after infestation around the larvae, a connective tissue capsule with a gradually formed internal hyaline layer is formed. The encapsulated larva has an oval ("lemon-like") shape measuring 0.5x (0.2-0.6) x 0.3 mm. The capsule is gradually impregnated with calcium salts, and the larvae can remain invasive for many years.

Pathogenesis of trichinosis

Larvae of Trichinella are released from the capsule under the influence of gastric juice. In the small intestine, the larvae penetrate into the superficial layer of the mucous membrane, develop to puberty, the females are fertilized, partially in the gut lumen. Larvae actively penetrate into the blood and lymphatic vessels, the blood and lymph flow through the body, lingering in the myocardium, the lungs, the liver and skeletal musculature.

Symptoms of trichinosis

The incubation period of trichinosis is from 1 to 4-6 weeks. In malignant disease, it is reduced to 1-3 days. The incubation period is up to 5-6 weeks when infected with northern natural Trichinella strains.

Trichinosis in children under equal conditions of infection is relatively easier than in adults. The most vivid symptoms of trichinosis - fever, muscle pain, facial edema - in young children are relatively less pronounced than in schoolchildren. However, small children notice lymphadenopathy with increased pharyngeal tonsils and sore throat, an increase in the spleen - it is mild, painless in palpation. In cases of severe course, there is a bright exudative or erythematous, hemorrhagic rash.

Diagnosis of trichinosis

Trichinosis is diagnosed with:

• on the basis of an epidemiological history - the use of raw or insufficiently cooked pork, wild meat, bacon, sausages, homemade canned food for 1-6 weeks before the appearance of clinical signs of invasion, acute febrile illness with bright allergic manifestations (facial edema, myalgia, skin rash , pulmonary syndrome, hypereosinophilia of the blood);
• according to the results of a laboratory study, detection of trichinella larvae in meat by trichinoscopy or by digestion in artificial gastric juice.

If it is impossible to investigate meat, serological reactions with trichinonellic diagnosticum (RSK, RIGA, IFA) are of significant help. They become positive already at the end of the 2nd week after infection. In doubtful cases with single diseases, one sometimes has to resort to a muscle biopsy (gastrocnemius, deltoid, broad back muscle), followed by histological examination and digestion of the muscle to detect the larvae.

Treatment of trichinosis

Assign mebendazole (vermox) at a dose of 5 mg / kg per day, 3 meals after meals for 5-7 days. With severe pain in the abdomen, dyspeptic disorders give no-shpa, papaverine, B vitamins.

Forecast

The prognosis for trichinellosis of moderate severity is favorable, with a severe course of the disease is determined by the speed of diagnosis and the implementation of complex specific and pathogenetic treatment. With trichinellosis of malignant course, only complex specific, pathogenetic and rehabilitation therapy can provide recovery from the first days of the disease.

Prophylaxis of trichinosis

Includes sanitary and veterinary control of meat products, sausages, canned meat, stabling pigs, prohibition of their house slaughter, feeding of carcasses of wild animals to pigs. Deratization in homes and outbuildings is important, preventing the access of wild rodents to pigsties. Prevention of the spread of trichinosis is achieved by the destruction (burning) of the invaded meat and emergency communication about the patient to the territorial sanitary-epidemiological station (SES) with the subsequent examination of the population and the elimination of the consequences of the invasion . Persons using insecticide meat undergo a preventive treatment with vermox at a dose of 5 mg / kg in 3 doses for 5-7 days, depending on the intensity of meat invasion.