The primary harm lies in liver damage to the patient, resulting from the metabolic byproducts and mechanical irritation caused by the parasites in the bile ducts of Chinese Taxillus Herb. The lesions mainly occur in the secondary bile ducts of the liver. In the initial stage (first stage) of infection, the lesions are not obvious. After prolonged grade III infection, localized dilation of the bile ducts occurs, accompanied by thickening of the duct walls. A large number of parasites can cause obstruction and bile stasis. If combined with bacterial infection, it may lead to cholangitis and biliary hepatitis. Chronic infection can result in significant proliferation of fibrous connective tissue, with noticeable atrophy of the nearby liver parenchyma. Increased secretion of glycoproteins in the bile ducts adheres to the surface of parasite eggs, acting as a core for stone formation, providing scaffolding and adhesion, and promoting the deposition of calcium bilirubinate. This ultimately leads to the formation of pigment stones (i.e., multiple intrahepatic stones).

bubble_chart Epidemiology

Human infection with Clonorchis sinensis is primarily distributed in the Far East, including China, Japan, Korea, Vietnam, and Southeast Asian countries. In China, infections have been reported in 24 provinces, municipalities, and autonomous regions, with prevalence rates ranging from 1% to 30%, though no cases have been documented in Qinghai, Ningxia, Xinjiang, Inner Mongolia, or Tibet. The range of infection in reservoir host animals is even broader, with higher prevalence and intensity of infection compared to humans, posing a potential threat to human populations. The key factor driving the prevalence of clonorchiasis in a region is the local population's habit of consuming raw or undercooked fish.

Infection occurs by ingesting fish containing metacercariae.

bubble_chart Pathogen

The Chinese liver fluke [Clonorchis sinensis (Cobbold, 1875) Looss, 1907], abbreviated as C. sinensis, is also known as the liver fluke.

bubble_chart Pathological Changes

After a prolonged period of grade III infection, localized dilation of the bile ducts occurs, accompanied by thickening of the duct walls. A large number of parasites can cause obstruction and bile stasis. If combined with bacterial infection, it may lead to cholangitis and cholangiohepatitis. Chronic infection can result in significant proliferation of fibrous connective tissue, with noticeable atrophy of the adjacent liver parenchyma. Increased secretion of glycoproteins in the bile ducts adheres to the surface of parasite eggs, acting as a core for stone formation, providing scaffolding and adhesion, and promoting the deposition of calcium bilirubinate. This ultimately leads to the formation of pigment stones (i.e., multiple intrahepatic stones). Additionally, both domestic and international data continue to suggest a certain correlation between Clonorchis sinensis infection and the occurrence of cholangiocarcinoma and hepatocellular carcinoma.

bubble_chart Clinical Manifestations

The clinical symptoms commonly include fatigue, upper abdominal discomfort, indigestion, abdominal pain, diarrhea, dull pain in the liver area, dizziness, and others, but many infected individuals show no obvious symptoms. Common signs include hepatomegaly, while splenomegaly is less frequent, and occasionally, poor development resembling dwarfism may be observed. In severe cases, advanced stages can lead to liver cirrhosis with ascites and even death.

Pathogen examination: The detection of eggs is the primary basis for diagnosis. Due to the small size of the eggs, the direct fecal smear method is prone to missing them in fistula disease, so egg concentration methods (such as water sedimentation centrifugation, ether sedimentation, etc.) and duodenal drainage bile centrifugation are commonly used for examination. These eggs resemble those of heterophyid flukes and are difficult to distinguish. Immunodiagnosis: Skin tests, indirect hemagglutination tests, counter-immunoelectrophoresis, enzyme-linked immunosorbent assays (ELISA), and indirect fluorescent antibody tests have been attempted for the auxiliary diagnosis of clonorchiasis. However, results vary significantly among patients, and there is notable cross-reactivity with other gastrointestinal parasite infections (particularly trematode infections), making these methods unsuitable for definitive diagnosis. Currently, they are only used for preliminary screening in epidemiological surveys. In recent years, some researchers have attempted methods such as sandwich ELISA to detect circulating antigens, which demonstrate higher sensitivity and specificity compared to circulating antibody detection methods.

bubble_chart Diagnosis

The detection of eggs is the primary basis for diagnosis. Immunodiagnosis: Intradermal tests, indirect hemagglutination tests, counter-immunoelectrophoresis, enzyme-linked immunosorbent assays (ELISA), and indirect fluorescent antibody tests have been attempted as auxiliary diagnostic methods for clonorchiasis. However, the results vary significantly among patients, and there is notable cross-reactivity with other gastrointestinal parasite infections (particularly trematode infections), making these methods unsuitable for definitive diagnosis. Currently, they are only used for preliminary screening in epidemiological surveys.

Actively treating patients and infected individuals is a proactive measure to protect public health and reduce the sources of pestilence. Currently, praziquantel is the drug of choice for treatment.

bubble_chart Cure Criteria

After thorough treatment, if no eggs are found in the stool upon examination after 1 to 2 months, it is considered cured.

bubble_chart Prevention

Make vigorous efforts to carry out health education and publicity to raise public awareness of the Bingchuan transmission routes, and consciously avoid eating raw or undercooked fish and shrimp. Improve cooking methods and change dietary habits, paying attention to separating knives, cutting boards, and utensils used for raw and cooked foods. Also, avoid feeding raw fish to cats and dogs.

Actively treating patients and infected individuals is a proactive measure to protect public health and reduce sources of pestilence. Currently, Praziquantel is the drug of choice for treatment.

Proper disposal of feces and changing fish farming practices are both important measures to prevent the spread of Clonorchis sinensis Bingchuan. Additionally, in line with production needs, cleaning pond sludge and disinfecting fish ponds can be somewhat effective in killing snails.

bubble_chart Complications

Bile duct obstruction, gall bladder stasis, pancreatitis

bubble_chart Differentiation

It is often misdiagnosed as pestilential hepatitis and should be differentiated from other digestive tract infections caused by Chinese Taxillus Herb parasites, especially trematode infections.