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Opisthorchiasis - Diagnosis
Medical expert of the article
Last reviewed: 03.07.2025
Diagnosis of opisthorchiasis is based on clinical, epidemiological and laboratory data: consumption of thermally untreated, lightly salted fish in endemic regions; fever, toxic-allergic syndrome; leukocytosis and eosinophilia in the blood; in the chronic phase - symptoms of cholecystopancreatitis, gastroduodenitis.
Signs of acute allergy and data from instrumental examination methods (ultrasound, cholecystography, CT, MRI) are revealed, indicating signs of dyskinesia of the gallbladder and biliary tract, decreased excretory function of the liver, dilation of the bile ducts, which are most characteristic of the acute stage of the disease. In the chronic stage, moderate eosinophilia (5-12%) is noted, sometimes anemia with normo- or macroblastic type of hematopoiesis. Liver functions (protein-synthetic, pigment, antitoxic) in uncomplicated opisthorchiasis remain normal or slightly decrease. With the development of hepatitis, cholecystitis, cholangitis, high eosinophilia is noted. The appearance of jaundice symptoms is combined with an increase in the activity of alkaline phosphatase with a relatively small increase in the level of ALT. Involvement of the pancreas in the process is indicated by an increase in fasting serum glucose, an altered curve with a sugar load, a decrease in trypsin, amylase and lipase in the duodenal contents and an increase in their content in the blood, an increase in diastase in the urine. Half of the patients have a decrease in gastric acidity.
Clinical diagnostics of opisthorchiasis uses EGDS, cholecystography, duodenal intubation, ultrasound of the abdominal organs, and determination of the acidity of gastric juice.
[ Specific laboratory diagnostics of opisthorchiasis
Parasitological diagnostics of opisthorchiasis in the acute stage is impossible, since helminths begin to release eggs only 6 weeks after the onset of invasion. To determine specific antibodies, ELISA is used. The following test systems are used:
- for the determination of IgM - "Opisthorchis-1gM-strip";
- for the determination of IgG - "Tiatop-strip";
- to determine specific CICs - "Opistorh-CIC-strip".
Parasitological examination of bile is the most reliable method for diagnosing opisthorchiasis. Microscopic examination of the sediment of three portions of bile is performed. Duodenal intubation is a complex and not always acceptable procedure, unsuitable for mass examinations. That is why coproovoscopy based on the study of the morphological features of opisthorchis eggs is the most common. Various methods are used in examining feces: qualitative formalin-ether, chemical-sedimentation Berezantsev, quantitative Stoll and semi-quantitative Kato. Fülleborn and Goryachev flotation methods are also used.
In case of minor invasion, opisthorchis eggs are not detected constantly, therefore, repeated parasitological examination of patients is necessary after procedures that stimulate bile flow (tubage according to Demyanovich, taking cholekinetics).
The final diagnosis of "opisthorchiasis" is established when the eggs of the cat fluke are found in the duodenal contents or in the feces, which begin to be excreted no earlier than 4-6 weeks after infection. In case of low-intensity invasion, before conducting a fecal examination, it is advisable to prescribe choleretic agents or blind probing according to Demyanov to the patient, as a result of which the probability of detecting helminth eggs increases.
When examining feces, enrichment methods (formaldehyde-ether, etc.) must be used. In case of a negative result, the examination of feces is repeated several times at intervals of 5-7 days. The examination of duodenal contents must be carried out within two hours of its receipt, since lysis of eggs occurs in the material during long-term storage.
Example of diagnosis formulation
B66.0. Chronic opisthorchiasis. Chronic cholecystopancreatitis (Opisthorhis felineus eggs in duodenal contents).
Differential diagnostics of opisthorchiasis
Differential diagnosis of opisthorchiasis is difficult due to the polymorphism and non-specificity of clinical symptoms.
The acute phase of opisthorchiasis must be differentiated from typhoid fever, acute respiratory infections, inflammatory diseases of the abdominal organs (cholecystitis, cholangitis, pancreatitis), helminthic infestations (trichinellosis, fascioliasis, paragonimiasis), blood diseases, pneumonia, acute intestinal infections, viral hepatitis.
Acute opisthorchiasis with signs of hepatitis differs from viral hepatitis by fever against the background of jaundice, more pronounced pain syndrome, high eosinophilia, increased alkaline phosphatase activity in combination with moderately pronounced signs of cytolytic syndrome.
Unlike acute respiratory infections, acute opisthorchiasis is characterized by mild catarrhal symptoms, enlargement and pain of the liver, and eosinophilia.
Differential diagnostics of opisthorchiasis in the chronic phase is carried out with fascioliasis, cholecystitis, pancreatitis, gastroduodenitis, chronic hepatitis of other etiologies.