What is Opisthorchiasis in children?
Opisthorchiasis is a chronic helminthiasis, in which the biliary system and the pancreas are predominantly affected.
In those children who are aboriginals of high-endemic foci, the disease in most cases occurs in subclinical form and is found in mature or old age. When children from non-endemic areas come to endemic areas, they have opisthorchiasis in acute form, which then becomes chronic.
Epidemiology. The disease is most often found in the Ob and Irtysh basin in Western Siberia and East Kazakhstan. Also sporadic cases and flashes are fixed in the basins of the Kama, Northern Dvina, Volga, Neman, Dnieper, in the center of the European part of Russia, in the Baltic States, Belarus, Germany, Eastern Europe.
O. viverritti invasion occurs in Thailand, Laos, Vietnam, Taiwan, India. Opisthorchiasis is a natural focal invasion that is widespread among fish-eating animals, but in endemic foci, humans are the main source of infection.
Opisthorchiasis child “picks up”, eating raw, frozen, dried, salted fish of the carp family: dace, ide, roach, chebak, sesana, bream, etc.
Opisthorchiasis affects 80-100% of the indigenous population of the north (both children and adults), since their diet often includes thermal, non-treated, highly invasive fish. In the north of Western Siberia, 80 to 100% of children by the age of 8 are already affected by opisthorchiasis.
Causes of Opisthorchiasis in children
In Russia and European countries, opisthorchosis provokes the flatworm Opistorchis felineus. It belongs to the flukes. In the countries of Southeast Asia, opisthorchosis provokes O. viverrin. This leaf-shaped parasite has a pointed head end. Its length is from 4 to 13 mm, width from 1 to 3.5 mm, thickness about 1 mm.
At the head end there is an oral sucker, and the abdominal sucker is located on the border between the first and second quarters of the body. Opistorchis are hermaphroditic – possess signs of both male and female. The body of the helminth is a bright brown shade, with translucent loops of the uterus, filled with eggs.
Opistorchis eggs are pale yellow, have an oval shape, a thin two-contour shell. At one end they have a cap, and at the other there is a styloid growth. The egg sizes are 0.01–0.019×0.023– 0.034 mm. The parasite produces about 1 thousand eggs per day.
In the bodies of children, adults and mammals, sexually mature opistorchises “settle” the bile ducts of the liver and the pancreatic ducts, the eggs they secrete into the ducts, from which they enter the intestine. With faeces, parasite eggs enter the environment.
Opisthorchis develops and multiplies in the intestine of the freshwater mollusk Bithynia inflata, from which after 2 months the tailed larvae – perkarin emerge. The second intermediate host is carp fish. In them, the larvae transform into metacercariae and become encysted.
Metatserkarii goes to the invasive stage in 1.5 months. It then looks like an oval cyst with a size of 0.24 to 0.34 mm. It has a thick connective sheath. Inside is a larvae covered with small spines. Puberty of metacercaria occurs in the body of the final host for 3-4 weeks. The entire development cycle of opistorchis takes 4-4.5 months. In humans, helminth can live for decades.
Pathogenesis during opisthorchiasis in children
Metacercariae are released from the membrane in the stomach and duodenum by digesting infected fish. In the common bile duct, for 3 to 5 hours, they enter the intrahepatic bile ducts.
When migrating and maturing, opistorhis produce metabolites that are toxic to the epithelium of the ducts. They activate the release of endogenous factors of inflammation by lymphoid and macrophage elements.
Symptoms that appear during infection depend on the amount of parasite in the body, as well as on the level of immunity of the child and his age. A common alert action is developing. Dystrophic processes in the liver and myocardium depend on cell proliferation in the walls of microvessels.
Imbalance in the production of peptide hormones plays a significant role in the disruption of the activity of the digestive organs. In children of the indigenous peoples of the North, the onset of the disease occurs in a subclinical form due to the fact that parasite antigens enter the body with the mother’s milk and even through the placenta.
In the chronic stage of opisthorchiasis in children, allergic phenomena are expressed to a small extent, immunosuppression is leading, which causes a complicated course of viral and bacterial infections, and also contributes to the development of bacterial carriage.
Symptoms of Opisthorchiasis in children
In children who live in highly endemic foci of opisthorchiasis, the disease often has a primary chronic course. Symptoms begin to appear in the middle of life or even in old age – they are provoked by concomitant diseases and intoxication.
In countries where there are foci of medium endemicity, the acute stage of opisthorchiasis is observed in children from 1 to 3 years, which manifests itself as subfebrile, epigastric pain, right upper quadrant, also exudative or polymorphic skin rashes, gastrointestinal disorders, catarrh of the upper respiratory tract. An increase in the liver, lymphadenopathy, hypoalbuminemia, and blood eosinophilia are recorded to 12–15%. After the initial manifestations, the erythrocyte sedimentation rate rises to 20-25 mm / h, a tendency to anemia is observed. The child is lagging behind in development.
In children from 4 to 7 years old, allergic symptoms are more pronounced, the level of eosinophilia is 20-25%, which is accompanied by leukocytosis up to 10-12×109 / l. In middle-aged and older children, after 2-3 weeks after a massive infection, a skin rash, marked dystrophic changes in the myocardium, fever, pulmonary syndrome in the form of “volatile” infiltrates or pneumonia are fixed. If the disease is particularly severe, then allergic hepatitis with gelation splenomegaly, jaundice, with eosinophilia at the level of 30-40%, ESR – 25-40 mm / h.
Acute manifestations of the disease can develop gradually, reaching a maximum by 1-2 weeks. Depending on the massiveness of infection, the acute period of opisthorchiasis in children lasts from 1 to 4 weeks, then the phenomena gradually subside. After infection for another 6 months, eosinophilia may be observed up to 10-15%.
In children in endemic foci, the chronic stage of the disease is manifested mainly by pronounced cholepathy, in more rare cases, gastroenteropathic syndrome occurs.
In infants and preschoolers, physical development slows down, appetite disappears, the stool becomes unstable, the liver is enlarged moderately (in rare cases, palpation causes painful sensations). A tendency to anemia is likely, but rarely.
Due to repeated infections, the symptoms peak to the age of 10-12 years. The main complaints are pains in the right hypochondrium, severity, instability of the stool, nausea, loss of appetite, which indicates the transition of hypertensive dyskinesia of the gallbladder to hypotonic.
Often, eosinophilia stays at 5–12% or less, fixing hypoalbuminemia and a tendency to anemization. By the age of 14-15, laboratory values often return to normal.
Classification. In acute opisthorchiasis in children, the disease may be asymptomatic, obliterated or clinical. Variants of the disease: hepatocholangitis, cholangitis, bronchopulmonary, typhoid.
Forms of chronic opisthorchiasis: latent and clinically pronounced; may occur with signs of cholepathy and gastroduodenopathy.
Congenital opisthorchiasis does not occur. Parasite antigens are transmitted through the placenta to the fetus from the mother. Specific antibodies in high-endemic foci are transmitted with milk to the newborn. Therefore, the disease in such children proceeds in a sub-personal form during invasion by these parasites.
Diagnosis of Opisthorchiasis in children
An epidemiological history is required for the diagnosis of acute epistorchiasis. The physician is informed about the use of thermal, untreated or insufficiently treated fish from the carp family. Also indicates opisthorchosis typical symptoms: acute fever or high subfebrile condition, skin rash, arthralgia, myalgia, pneumonia, catarrhal symptoms, jaundice, pneumonia, eosinophilic leukocytosis. A positive serological reaction with opisthorchosis diagnostics also indicates this disease. Used methods IFAJU RNA. One and a half months after infection, the parasite’s eggs can be found in the bile and feces of the patient.
Opisthorchiasis in the chronic stage is diagnosed on the basis of epidemiological history, symptomatology of cholepathy or gastroenteropathy with exacerbations and remissions. Confirmation of the diagnosis is carried out by detecting parasite eggs in the feces and duodenal contents.
Ultrasound shows biliary tract dyskinesia of mainly hypertensive type in young children and hypotonic type in older ones.
Treatment of Opisthorchiasis in children
Opisthorchiasis at the acute stage at high temperature and organ damage is treated first with detoxification therapy, antihistamine preparations, and calcium salts. In severe cases of the disease should be taken orally or enter parenterally moderate doses of glucocorticoids in the course of 5-7 days. Requires rapid withdrawal of drugs. Cardiovascular agents are also used to treat severe forms of opisthorchiasis in children.
After normalization of the body temperature of the sick child and the onset of positive ECG dynamics (the best option is its normalization), the elimination of focal changes in the lungs is followed by one-day treatment with azinox (biltricid, praziquantel). The dose is 60-75 mg / kg, divided into 3 doses, the interval between which should be 4 hours or more. Take the drug after meals.
Prefer diet 5, be sure to limit the intake of fats and coarse fiber. There is no need for the appointment of a laxative. Treatment is accompanied by the mandatory intake of antihistamines, the introduction of ascorbic acid and calcium salts.
It is obligatory to monitor the effectiveness of treatment after three and six months with the help of a threefold study of feces by the method of Kato and duodenal contents. If, after half a year, the parasite’s eggs are detected by a study, you can reapply the azinoxa treatment course. If necessary, dispensary observation of children and pathogenetic therapy is carried out for 3 years after the last course of treatment of opisthorchiasis.
With a timely diagnosis and comprehensive adequate treatment, the prognosis for opisthorchiasis in children is favorable.
Prevention of opisthorchiasis in children
Specific preventive measures:
- Eat fish carp family strictly after sufficient heat treatment.
- In the foci of invasion, educate parents about hygiene standards, in particular, they convey the idea of the inadmissibility of feeding young children with raw fish or using it as a nipple.
General preventive measures:
- Prevent sewage from entering river basins.
- Destroy mollusks, intermediate hosts of opistorhis.
- To monitor the contamination of fish with parasites at the production and distribution points.