Schistosomiasis and Hepatobiliary Diseases

Introduction to schistosomiasis and hepatobiliary diseases Schistosomiasis is a serious parasitic disease that endangers human health and has a long history and is widespread. The human body is infected by contact with the infected water. The adult is mainly parasitic in the portal vein system. The complex immunopathological reaction caused by the deposition of the eggs can cause damage to the whole body and tissues. This article focuses on the hepatobiliary caused by schistosomiasis closely related to surgery. Department of disease. The prevalent schistosomiasis in China is mainly caused by Schistosoma japonicum infection. The eggs are excreted in the feces of the patients, and the edulis are hatched in the water. The snails are drilled into the middle host, and the snails develop into the scorpion and escape into the water. When the person comes into contact with the infected water, the scorpion is drilled into the skin or The mucous membrane becomes a child worm. The worm enters the right heart to the pulmonary circulation through the vein or lymphatic vessel, and then enters the portal vein through the capillaries into the portal vein. Finally, the liver develops into an adult worm, which is parasitic in the portal system. The snail is an essential intermediate host, and the human and livestock are Final host. basic knowledge The proportion of the disease: this disease is rare, mostly occurs in the epidemic area of schistosomiasis, the incidence rate is about 0.0001%-0.0005% Susceptible people: no specific population Mode of infection: infected water infection Complications: upper gastrointestinal bleeding, hepatic encephalopathy, viral hepatitis, typhoid, peritonitis, appendicitis, intestinal obstruction, colon cancer

Schistosomiasis and causes of hepatobiliary diseases

(1) Causes of the disease

The prevalent schistosomiasis in China is mainly caused by Schistosoma japonicum infection. The eggs are excreted in the feces of the patients, and the edulis are hatched in the water. The snails are drilled into the middle host, and the snails develop into the scorpion and escape into the water. When the person comes into contact with the infected water, the scorpion is drilled into the skin or The mucous membrane becomes a child worm. The worm enters the right heart to the pulmonary circulation through the vein or lymphatic vessel, and then enters the portal vein through the capillaries into the portal vein. Finally, the liver develops into an adult worm, which is parasitic in the portal system. The snail is an essential intermediate host, and the human and livestock are Final host.

(two) pathogenesis

1. Liver damage: It has been proven that the complex immunopathological response caused by eggs is the main cause of schistosomiasis. The liver is the main organ of schistosomiasis. The eggs reach the liver with blood flow and are deposited in the portal vein of the liver. Branch and entrance form granuloma, granuloma is the pathological basis of the disease, and the formation of granuloma is a T cell-mediated immune response, the allergen is the mature oocyst excrement - soluble egg antigen (SEA) The granuloma causes portal vein inflammation and fibrosis around the portal vein. As the disease progresses, it forms a trunk-type fibrosis characterized by schistosomiasis cirrhosis and portal hypertension. The lesion mainly occurs in the portal area, and the hepatic lobules are not. Suffering from severe damage, generally no hepatocytes regenerate nodules, so this portal hypertension is anterior, but studies have shown that some patients also have hepatocyte nodular hyperplasia, according to Jiang Shaoji et al. There is an increase, there may be factors of sinus occlusion, schistosomiasis cirrhosis rarely evolved into primary liver cancer.

2. Biliary damage: compared with the prevalence of schistosomiasis, biliary system lesions are less common, because the schistosomiasis in the portal system is deposited in the gallbladder and bile duct submucosa through the vascular anastomosis or the worms stay in the migration process. Due to the development of biliary tract, schistosomiasis eggs can form local fibrous scar stenosis or schistosomiasis granuloma can cause biliary obstruction. The schistosomiasis can form eosinophilic granuloma in the gallbladder, and eggs can also occur. Calcification, the gallbladder wall fibrous tissue hyperplasia, such as located in the gallbladder neck can narrow the neck; adult or eggs in the gallbladder can become the core of the stone; gallbladder wall mucosal damage can form ulcers and biliary bleeding; long-term inflammatory infiltration of the gallbladder wall Or schistosomiasis granuloma formation can occur in the gallbladder-intestinal fistula with adhesion to the surrounding intestinal tract. There is no definite evidence of a causal relationship between gallbladder schistosomiasis and gallbladder cancer.

3. Colon: The lesion is rectal, sigmoid colon, descending colon is the heaviest, transverse colon, appendix followed by early mucosal congestion and edema, flaky hemorrhage, mucous membrane with superficial ulcer, etc. Chronic patients with fibrous tissue hyperplasia, intestinal wall thickening It can cause intestinal polyps and colon stenosis, mesenteric thickening and shortening, lymph node enlargement and reticular tangles into a mass, forming a mass, intestinal obstruction can occur, eggs are deposited in the appendix, easy to induce appendicitis.

4. spleen: early mild hyperemia, edema, soft, advanced cirrhosis caused by portal hypertension, spleen congestion, tissue hyperplasia, fibrosis, thrombosis, progressive enlargement, spleen can appear, secondary spleen hyperfunction.

5. Ectopic damage: refers to the pathological changes of the eggs and/or adults that are parasitic outside the portal system. The lungs and brain are more common. The lung lesions are interstitial granuloma with peribulum infiltration. The brain disease is caused by granuloma of the parietal lobe and temporal lobe, which occurs mostly from 6 months to 1 year after infection.

Schistosomiasis and prevention of hepatobiliary diseases

1. Control the source of infection In the endemic areas, the patients and sick animals are censused every year.

2. Cutting off the transmission route to eliminate snails is the key to prevent this disease. The feces must be treated harmlessly to protect the water source and improve water use.

3. It is strictly forbidden to swim in the infected water, play in the water, and wear protective clothing and anti-tailing agent when contacting the infected water.

Schistosomiasis and complications of hepatobiliary diseases Complications upper gastrointestinal bleeding hepatic encephalopathy viral hepatitis typhoid peritonitis appendicitis intestinal obstruction colon cancer

1. Upper gastrointestinal bleeding is an important complication of advanced patients, the incidence rate is about 10%. Most of the bleeding sites are the lower esophageal and gastric fundus coronary veins, which are induced by mechanical damage and excessive force. It is characterized by hematemesis and black stools. The amount is generally larger.

2. Patients with advanced hepatic encephalopathy complicated with hepatic encephalopathy are mostly ascites type, mostly due to massive bleeding, a large amount of ascites, excessive diuresis and so on.

3. Infection due to the patient's immune function decline, hypoproteinemia, portal hypertension, etc., easily complicated by infection, such as viral hepatitis, typhoid fever, peritonitis, Salmonella infection, appendicitis.

4. Intestinal complications schistosomiasis caused by severe colonic lesions caused by intestinal stenosis, may be complicated by incomplete intestinal obstruction, sigmoid colon and rectum, schistosomiasis patients with colon granuloma may be complicated by colon cancer, mostly adenocarcinoma, malignant To a lesser extent.

Schistosomiasis and symptoms of hepatobiliary diseases Common symptoms Lymph node enlargement Portal hypertension High pressure Diarrhea Abdominal pain Hepatosplenomegaly

1. History of epidemics and contact with infected water.

2. Clinical manifestations There are intermittent or relaxation fever in the acute phase, cercaria dermatitis, urticaria, hepatosplenomegaly, abdominal pain, diarrhea, generalized lymphadenopathy; no obvious symptoms in the chronic phase, a few patients with unexplained abdominal pain, diarrhea Liver and splenomegaly, if complicated with hepatobiliary damage, cirrhosis, portal hypertension, cholecystitis and (or) symptoms and signs of bile duct inflammation may occur.

Examination of schistosomiasis and hepatobiliary diseases

1. Blood picture: The main increase of eosinophils in the peripheral blood of patients with schistosomiasis is that the total number of white blood cells is above l0×l09/L, and eosinophils generally account for 20%40%. More than 90%, chronic schistosomiasis patients generally mildly increased within 20%, while patients with extremely severe acute schistosomiasis often do not increase or even disappear, advanced patients often cause red blood cells, white blood cells and thrombocytopenia due to hypersplenism.

2. Liver function test: serum globulin increased in patients with acute schistosomiasis, serum ALT, AST increased slightly, late stage patients with liver fibrosis, serum albumin decreased, globulin increased, often the ratio of albumin to globulin was inverted Phenomenon, chronic schistosomiasis, especially in asymptomatic patients, liver function tests are mostly normal.

3. Fecal examination: Examination of eggs and hatching in the feces is the direct basis for the diagnosis of schistosomiasis, but the detection rate is generally higher in the acute phase, while the positive rate in the chronic and advanced patients is not high, and the modified Kato thick smear method is commonly used. Or check the eggs with a transparent method.

4. There are many immunological examination methods, and the sensitivity and specificity are high. The blood collection is small and easy to operate. However, because the antibody in the serum of the patient lasts for a long time after the cure, it cannot distinguish the past infection from the current patient, and has a fake. Positive, false negative and other characteristics, in recent years, the use of monoclonal antibodies to detect patients with circulating antigen micro-method may diagnose active infections, can be used as a reference for assessment of efficacy, is the current development of immunological diagnosis.

(1) Intradermal test: It is an allergic reaction. If the subject has been infected with schistosomiasis, there is a corresponding antibody. When the subject is injected intradermally with a small amount of schistosomiasis antigen, the antigen binds to the corresponding antibody on the cell surface. A local tissue reaction occurs, which is red, swollen, and itchy, that is, a positive reaction. As a screening method for infected with schistosomiasis, a positive person needs further examination.

(2) Ring Egg Precipitation Test (COPT): When the secretion of the hairy mites in the mature eggs is combined with the corresponding antibodies in the serum of the schistosomiasis patients, a specific precipitate is formed around the eggs, which is a positive reaction and can be used as a diagnosis. Patients and assessment of efficacy.

(3) Indirect hemagglutination test (IHA): The soluble schistosome egg antigen is adsorbed on the surface of red blood cells to make it become sensitized red blood cells. When the red blood cells meet the patient's serum, the red blood cells are bound by the antigen adsorbed on the cell surface and the specific antibody cells. Passive agglutination, visible positive reaction to the naked eye, in the epidemic area, the method can be used as a method of screening or comprehensive investigation.

(4) Enzyme-linked immunosorbent assay (ELISA): detection of specific antibodies in the serum of patients, making them antigen-antibody complexes, which are combined with special enzymes to develop color. This method can be used for diagnosis and evaluation of therapeutic effects. in accordance with.

(5) Circulating antigen enzyme immunoassay (EIA): the presence of circulating antigen indicates active infection, and the circulating antigen level in serum and urine has a good correlation with the fecal egg count. This method is sensitive, specific, simple and rapid. The diagnosis of schistosomiasis, the evaluation of curative effect and the evaluation of prevention and treatment effects are of great value.

5. B-type ultrasound examination: can determine the degree of liver fibrosis, visible liver, spleen volume changes, portal vein thickening is a change in reticulum, and can be positioned for liver biopsy.

6. CT scan: The liver capsule and the intrahepatic portal vein area of patients with advanced schistosomiasis often have calcification. CT scan can show specific images such as thickening and calcification of liver capsule, and severe liver fibrosis can be expressed as turtle-like image.

Diagnosis of schistosomiasis and hepatobiliary diseases

The history of exposure to schistosomiasis is a necessary condition for diagnosis and should be carefully interrogated, combined with clinical manifestations and signs and parasitology and immunological examinations, based on which the diagnosis can be determined.

Acute schistosomiasis can be misdiagnosed as typhoid fever, amebic liver abscess, miliary tuberculosis, etc., and significant increase in eosinophils in blood is important. Chronic schistosomiasis liver splenomegaly should be differentiated from jaundice-free viral hepatitis. Appetite loss, fatigue, liver pain and liver function damage are more obvious, schistosomiasis patients have diarrhea, blood donors stool hatching positive, and more hair mites, easy with amoebic dysentery, chronic sputum identification, advanced schistosomiasis Different from portal vein and post-necrosis cirrhosis, the former often has a history of chronic diarrhea and hemorrhage. Portal vein hypertension is more common in the spleen and lower esophageal varices. Liver function damage is lighter, and jaundice, spider mites and liver palm are less common. However, it is still necessary to identify multiple pathogens and immunological examinations. In addition, patients with epilepsy in the endemic areas should be excluded from cerebral schistosomiasis.

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