Human clonorchosis is a biohelminthiasis from the group of trematodoses, characterized by a predominant lesion of the biliary tract, pancreas, and liver parenchyma.
Epidemiology
The main source of invasion is a person infected with clonors. In addition, dogs and cats infest ponds . Chinese fluke is widespread in Japan, Vietnam, China, North Korea, the Amur basin, the Ob and Primorye. Helminth eggs secreted with feces, when released into the aquatic environment, are swallowed by mollusks, in the body of which cercariae (larvae) form after about 14 days. When larvae enter the body of fish and cancers from the intestine, they begin to actively move into the muscles and subcutaneous tissue. Thus, metacercariae is formed. A person becomes infected with a clonorchosis by eating raw, insufficiently thermally processed fish or crayfish. This is how clonorchiasis develops. Symptoms in patients, as a rule, begin to appear after the pathogen enters the small intestine.
Suckers: characteristic
Trematodes (flukes) - helminths related to the type of flatworms. As a rule, they have a leaf shape. Their size varies over a wide range from 0.1 mm to 15 cm in length. Chinese fluke can parasitize in animals and humans. All types of flukes lead a parasitic lifestyle.
Morphology and biology of flukes
The body of the trematode is compressed in the dorso-ventral direction. The cuticle, together with the muscle layer, forms the musculocutaneous bursa, in which the internal organs are located. Trematodes are fixed using special muscle organs - the suction cup. There can be two - oral and abdominal. The fixation organs also include spikes on the cuticle and glandular fossa.
Digestive system
In the front of the body is located the oral sucker, at the bottom of which is the mouth opening. The pharynx (pharynx) and the elongated esophagus follow the mouth. Intestinal tube - two blind-ending trunks. As a rule, flat helminths have no anus. Residues of non-hydrolyzed food are thrown out through the mouth opening. Partially, the feeding of flatworms can be carried out through the tegument.
Nervous and excretory system
The nervous system consists of nerve nodes located under the throat and trunks extending to other parts of the body. The excretory system is represented by a complex system of tubules that form two excretory canals.
Reproductive system
The reproductive system of trematodes is very well developed. Flukes (except representatives of the genus Schistosomatata) are hermaphrodites (bisexual creatures).
The male reproductive apparatus, as a rule, consists of two testes. From them depart the vas deferens, which are connected into a common deferent duct. It is usually enclosed in the genital bursa (a special muscular sac). The final part of the vas deferens is the cirrus (copulatory organ).
The female reproductive system includes the ovary, oviduct, ootype, testis, zheltochniki, Laurel channel, Melis body and uterus, which ends in the female genital opening.
Etiology
The causative agent of clonorchosis is a trematode - a Chinese fluke. This helminth belongs to the family Opisthorchidae - Clonorchis sinensis. Helminthiasis was first described by McConnell in 1874. A Chinese fluke in the human body can parasitize up to 40 years. The body of the helminth is flat, lanceolate, 10–20 mm long and 2–4 mm wide. Eggs of flukes are light golden in color; a cap is clearly visible at one of the poles. Clonorchis sinensis in the adult stage can parasitize both in humans and carnivorous mammals. The latter are definitive hosts. Freshwater mollusks act as intermediate ones, freshwater crayfish and cyprinids are additional ones.
Trematode Life Cycle
The life cycle of flukes consists of 4 periods:
- embryogony;
- parthenogony;
- cystogonia;
- maritogony.
Embryogony is the period of embryonic development of the germ cell in the trematode egg from fertilization to the release of miracidia. The duration of this phase is about a month. Parthenogony is the post-embryonic period of the development of the larval stage in the body of the intermediate host. The presented phase begins from the formation of a sporocyst to the release of cercaria into the environment. The duration of this period can vary from two weeks to five months.
Cystogonia is the process of converting cercaria to adolescari (in the environment) or metacercaria (in the body of an additional host). The duration of cystogonia is from several hours to two months.
Maritogony is the period of development of flukes in the body of the definitive host to the sexually mature stage (imago), which secretes 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 mother to child by the transplacental route. Therefore, although such people are diagnosed with the disease, however, it has a milder course. The development of pathology is based on the mechanical effect of the fluke, the attachment of secondary microflora, neurotrophic disorders and toxic-allergic reactions. In addition, clonors cause cirrhotic changes in the liver.
Symptoms of the disease
If you have been diagnosed with clonorchiasis, the pathology symptoms are similar to opisthorchiasis. In the acute phase of infection, there is a decrease in appetite, malaise, general weakness, and allergic reactions. With the progression of the disease, signs characterizing damage to the liver, pancreas and biliary tract appear. Patients complain of fever, as well as severe pain, localized in the right hypochondrium.
Possible complications of the disease
It could be:
- chronic cholecystitis;
- cirrhosis of the liver;
- chronic gastroduodenitis;
- pancreatic and stomach cancer;
- chronic hepatitis.
Pathology diagnostics
The diagnosis is made on the basis of epizootic and clinical data, as well as the results of helminthocoprological studies. To clarify the diagnosis, a biochemical blood test (total protein, blood sugar, bilirubin, activity of alkaline phosphatase, aminotransferases, amylase, trypsin and lipase) is performed, instrumental (cholecystography, ultrasound examination of the gallbladder, liver, pancreas, fibrogastroduodenoscopy) and serological (RID) are prescribed , RNGA, PCR) research methods.
Therapy
If the patient is diagnosed with clonorchiasis, treatment should be comprehensive:
- diet therapy;
- anthelmintic drugs ("Biltricid", "Niklofolan", "Chloxil");
- antihistamines (Calcium Gluconate, Loratidine, Suprastin);
- non-steroidal anti-inflammatory drugs ("Ibuprofen", "Nimisulide");
- enzymes (Panzinorm, Mezim, Creon);
- sorbents (Enterosgel, Ataxil, Polysorb);
- antispasmodics ("Papaverine", "No-shpa", "Mebeverin");
- macrolides (Oleandomycin, Spiramycin, Azithromycin, Roxithromycin, Flurithromycin);
- choleretic drugs (Xylitol, Sorbitol, corn stigmas, immortelle, rosehips, mint leaves);
- hepatoprotectors (Essentiale, Ursokhol).