Chinese trematode. Clonorchiasis: symptoms, treatment. Human parasites

Human clonorhosis is a biogelmintosis from the group of trematodes, characterized by a predominant lesion of the bile ducts, pancreas and liver parenchyma.

Epidemiology

The main source of infestation is a person infected with clonorchids. In addition, water bodies are invaded by dogs and cats. The Chinese trematode is widely distributed in Japan, Vietnam, China, North Korea, the Amur, Ob and Primorye basins. Eggs of helminths, excreted with feces, when ingested into aquatic environment are swallowed by mollusks, in the body of which after about 14 days cercariae (larvae) are formed. When larvae enter the body of fish and crayfish from the intestine, they begin to actively move into the muscles and subcutaneous tissue. Thus, the metacercaria is formed. A person clonorchosis gets infected by eating raw, insufficiently thermally processed fish or crayfish. And the clonorchosis is developing. Symptoms in patients, as a rule, begin to appear after the entry of the pathogen into the small intestine.

Flukes: characteristic

Trematodes (flukes) are helminths that are related to the type of flatworms. As a rule, they are leaf-shaped. Their size varies in a wide range from 0.1 mm to 15 cm in length. The Chinese trematode can parasitize in the body of animals and humans. All types of flukes are parasitic.

Morphology and biology of flukes

The body of the fluke is compressed in the dorso-ventral direction. The cuticle together with the muscular layer form the skin-muscular bursa, in which the internal organs are located. Trematodes are fixed by means of special muscular organs - suckers. They can be two - oral and abdominal. The organs of fixation can also include spines on the cuticle and glandular fossae.

Digestive system

In front of the body, the oral sucker is localized, at the bottom of which there is a mouth opening. Behind the mouth follows pharynx (pharynx) and elongated esophagus. Intestinal tube - two blind-end trunks. The anal opening of flat helminths, as a rule, does not. The remains of unhydrolyzed food are ejected through the mouth opening. Partly feeding flat worms can be carried out through the tegument.

Nervous and excretory system

The nervous system consists of nerve nodes located under the pharynx, and trunks that extend into other parts of the body. The excretory system is represented by a complex system of tubules, which form two excretory canals.

Sexual system

The reproductive system in trematodes is very well developed. Flukes (except for representatives of the genus Schistosomatata) are hermaphrodites (bisexual creatures).

Male genitalia, as a rule, consists of two testes. From them depart the vas deferens, which are connected to the common vas deferens. It is usually enclosed in the genital bursa (special muscular sac). The final part of the vas deferens is cirrus (copulatory organ).

The female genital apparatus includes the ovary, the oviduct, ootype, spermathecal, vitellaria, the Laurer channel, the Melis body and the uterus, which ends with the female genital orifice.

Etiology

The causative agent of the clonorchosis is the trematode - the Chinese trematode. This helminth belongs to the family Opisthorchidae - Clonorchis sinensis. For the first time helminthiasis was described by McConnell in 1874. Chinese trematode in the human body can parasitize up to 40 years. The helminth body is flat, lanceolate, 10-20 mm long and 2-4 mm wide. Egg trematodes have light-golden color, on one of the poles the lid is clearly visible. Clonorchis sinensis in the adult stage can parasitize both in humans and in carnivorous mammals. The latter are definitive hosts. As interim serve freshwater mollusks, additional - freshwater crayfish and carp fish.

Life cycle of trematodes

The life cycle of trematodes consists of 4 periods:

• Embriogony;
• Parthenongony;
• Cystonium;
• Marigonians.

Embryogonia is the period of embryonic development of the embryonic cell in the trematode egg from fertilization to the exit of miracidia. The duration of this phase is about a month. Parthenogonia is a postembryonic period of development of the larval stage in the body of the intermediate host. The presented phase begins from the formation of sporocysts to the release of cercariae into the environment. The duration of this period can vary from two weeks to five months.

Cystoinia is the process of transforming cercaria into adolescaria (in the environment) or metacercaria (in the body of an additional host). The duration of the cystonia is from several hours to two months.

Maritogonia is a period of development of flukes in the organism of the definitive host to the adult stage (imago), which releases eggs into the environment. The duration of this stage is from one week to two months.

Pathogenesis

Patients living in endemic areas develop immunity, which is transmitted from the mother to the child by the transplacental route. Therefore, in such people, although the disease is diagnosed, but it has a lighter course. At the heart of the development of pathology is the mechanical effect of the flukes, the attachment of secondary microflora, neurotrophic disorders and toxic-allergic reactions. In addition, clonorchias cause cirrhotic changes in the liver.

Symptoms of the disease

If you have a clonorhoz diagnosis, the symptoms of pathology are similar to opisthorchiasis. In the acute phase of infection, decreased appetite, malaise, general weakness, manifestations of allergic reactions. With the progression of the disease, there are signs characterizing the damage to the liver, pancreas and bile ducts. Patients complain of fever, as well as severe pain localized in the right hypochondrium.

Possible complications of the disease

It can be:

• chronic cholecystitis;
• cirrhosis of the liver;
• Chronic gastroduodenitis;
• Cancer of the pancreas and stomach;
• Chronic hepatitis.

Diagnosis of pathology

The diagnosis is based on epizootic and clinical data, as well as the results of helminthoprooprologic studies. To clarify the diagnosis, a biochemical blood test is performed (total protein, blood sugar, bilirubin, activity of alkaline phosphatase, aminotransferases, amylase, trypsin and lipase), prescribe instrumental (cholecystography, ultrasound of the gallbladder, liver, pancreas, fibrogastroduodenoscopy) and serological , RNGA, PCR) research methods.

Therapy

If the patient is diagnosed with clonorchiasis, the treatment should be comprehensive:

• Diet therapy;
• Anthelmintic preparations ("Biltricid", "Nichlofolan", "Khloksil");
• Antihistamines ("Calcium Gluconate", "Loratidine", "Suprastin");
• Nonsteroidal anti-inflammatory drugs (Ibuprofen, Nimisulid);
• Enzymes (Penzinorm, Mezim, Creon);
• Sorbents (Enterosgel, Ataxil, Polysorb);
• Antispasmodics (Papaverin, No-shpa, Mebeverin);
• Macrolides ("Oleandomycin", "Spiramycin", "Azithromycin", "Roxithromycin", "Flurithromycin");
• Cholagogue preparations ("Xylitol", "Sorbitol", corn stigmas, immortelle, hips, mint leaves);
• Hepatoprotectors (Essentiale, Ursohol).