Schistosoma eggs found in fecal or rectosigmoid mucosal biopsy

Introduction The schistosomiasis is found in the fecal or rectal or sigmoid mucosal biopsy. It is one of the diagnostic basis for pulmonary schistosomiasis. The schistosomiasis is caused by the schistosomiasis of the worms, the adult worms in the lungs, development, parasitism, or the eggs in the lung tissue. It is the most common ectopic schistosomiasis caused by inflammation in the lungs, abscess, granuloma, and pseudotuberculosis. It is often accompanied by symptoms such as cough, chest pain, hemoptysis, asthma, and difficulty breathing.

Cause

1. Parasitic schistosomiasis: Schistosomiasis is mainly parasitic in the blood vessels of the human portal system. The eggs produced by adults are mainly deposited in the intestinal mucosa and liver tissue. If the adult parasitic and insect eggs are deposited in an organ tissue beyond this range and cause damage, it is called ectopic schistosomiasis. The schistosomiasis eggs can be circulated into the lungs through the collaterals of the hepatic vein or portal vein and deposited in the lung tissue. Occasionally, schistosomiasis is parasitic in the lungs, and even females and males share the eggs. The worms that reach the lungs can pass through the alveolar wall capillaries and enter the thoracic cavity, mediastinum, and sacral to reach the abdominal cavity and enter the portal system.

2. The cercaria enters the skin when it comes into contact with the human body in the epidemic water, and the tail is turned into a child worm. The child worm stays under the skin for 5-6 hours, that is, enters small blood vessels and lymphatic vessels, and generally flows with the blood on the second day after the invasion. The right heart and pulmonary artery reach the capillaries of the lungs. On the 8th to 9th day after the invasion, the larvae reach the portal system and develop into adult worms. After that, the adults are retrogradely parasitized to the superior iliac vein and the inferior mesenteric vein and lay eggs from infection to production. Eggs are generally 4 to 6 weeks.

3. Pulmonary chronic schistosomiasis is formed after the acute phase or due to repeated infection and long-term invasion of small cercariae in the lungs. The migration of the worm to the lungs can cause pathological changes in allergic pneumonia such as hyperemia, hemorrhage, and eosinophil infiltration. These lesions often appear 1 to 2 weeks after infection and disappear quickly. The reaction caused by the deposition of eggs in the lungs varies with the degree of maturity: mature eggs can cause tissue necrosis and acute exudative inflammation. Endometritis and eosinophilic granuloma often occur in the deposits of eggs. An acute abscess can be formed. As the egg dies, the abscess is gradually absorbed to form a granuloma. The granuloma contains a large number of epithelial cells and is heterogeneous. The giant cells are very similar to the nodules of tuberculosis, and are called "false tuberculosis". The granuloma can be gradually fibrotic, and the eggs can be calcified after death; the immature eggs cause less tissue reaction, although there are also "pseudotubules", but the eosinophils and neutrophils do not infiltrate much. . Chronic pulmonary schistosomiasis is mainly caused by mechanical or chemical stimulation of schistosomiasis eggs deposited in the lungs, causing pulmonary interstitial, bronchial submucosal congestion, edema, ulcer formation, bronchial, bronchioleal stenosis, mucosal epithelium and fibrous tissue. Hyperplasia, cell infiltration, etc.

an examination

Related inspection

Schistosomiasis egg-precipitation test chest smear parasite examination direct smear antigen intradermal test fecal microscopy

Clinical manifestation

The schistosomiasis endemic area has a history of contact with the infected water and has other symptoms of general schistosomiasis. X-ray films suggest small or miliary lesions or inflammatory lesions in the lungs, with varying degrees of cough, chest pain, hemoptysis, asthma, and difficulty breathing. The schistosomiasis eggs were found in the sputum, or the bronchial brushing and bronchial mucosa biopsy found the schistosomiasis eggs. Schistosomiasis eggs were found in the fecal or rectal, sigmoid colon mucosa. Blood eosinophils increase, immunological tests such as skin test positive, ring egg test positive, etc., can help diagnose.

Laboratory inspection

1, the total number of white blood cells and eosinophil count: acute white blood cell count and eosinophil count increased, eosinophils generally accounted for 15% to 20%, even up to 70%, eosinophils increased degree and infection Disproportionately, the number of critically ill patients may not increase, or vice versa, or substitute for neutrophils, which is a sign of danger. Eosinophils in patients with chronic schistosomiasis generally do not exceed 20%, while the increase in advanced cases is not obvious. It may also be accompanied by a decrease in hemoglobin and abnormal liver function.

2, stool examination: the positive rate of direct smear is not high, so the precipitation and hatching methods are generally used.

3, sputum examination: sputum examination can also find eggs or edulis by direct smear method or precipitation and hatching method.

4, rectal mucosal biopsy: rectal mucosal biopsy or tablet can find eggs.

5, immunological examination: immunological examination such as schistosomiasis antigen intradermal test, ring egg precipitation test, cercaria membrane test and immunoelectrophoresis detection of antigen and other methods can provide auxiliary diagnosis.

Differential diagnosis

Pulmonary schistosomiasis should be differentiated from miliary tuberculosis, chronic bronchitis, bronchial asthma and non-specific lobular pneumonia.

1. It is mainly based on the history of schistosomiasis endemic areas and contact with infected water, and has other symptoms of general schistosomiasis. X-ray films suggest small or miliary lesions or inflammatory lesions in the lungs, with varying degrees of cough, chest pain, hemoptysis, asthma, and difficulty breathing. The schistosomiasis eggs were found in the sputum, or the bronchial brushing and bronchial mucosa biopsy found the schistosomiasis eggs. Schistosomiasis eggs were found in the fecal or rectal, sigmoid colon mucosa. Blood eosinophils increase, immunological tests such as skin test positive, ring egg test positive, etc., can help diagnose.

2, laboratory examination: the total number of white blood cells and eosinophil count increased in the acute phase, eosinophils generally accounted for 15% to 20%, even up to 70%, the increase in eosinophils is not proportional to the severity of infection, severe Patients may not increase, or vice versa, or substitute neutrophils, which is a sign of danger. Eosinophils in patients with chronic schistosomiasis generally do not exceed 20%, while the increase in advanced cases is not obvious. It may also be accompanied by a decrease in hemoglobin and abnormal liver function. The positive rate of direct smear of stool examination is not high, so precipitation and hatching methods are generally used. The sputum can also be found by direct smear or by precipitation and hatching. Eggs can be found by rectal mucosal biopsy or tableting. Immunological tests such as intradermal test of schistosomiasis antigen, ring egg sedimentation test, cercaria membrane test and immunoelectrophoresis detection of antigen can provide auxiliary diagnosis.

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