Echinococcosis granulosus

　　Alveolar echinococcosis is a disease caused by the larvae of Echinococcus granulosus in animals. Then, how is alveolar echinococcosis caused? The following experts introduce the etiology of alveolar echinococcosis:

　　1, Infectious source

　　The infectious source is dogs infected with Echinococcus granulosus. The eggs have good tolerance to temperature and are suitable for transmission in pastoral areas.

　　2, Transmission routes

　　It is transmitted by eating the eggs of the worm, with intermediate hosts including humans. The main route of infection is through the oral intake of food. The main source of human infection is drinking water and food. People engaged in pastoral production, hunting, and fur processing are at high risk.

　　3, Susceptible population

　　Patients are mostly young and middle-aged farmers and herdsmen, most of whom are infected during childhood and become ill in their youth.

　　Common complications of liver hydatid cysts include secondary infection and cyst rupture. The pathological changes caused by infection are similar to those of liver abscess, but the symptoms are relatively mild. Cyst rupture of liver hydatid cysts is a common and serious complication, often caused by secondary infection, trauma, or puncture, and the consequences of rupture into the abdominal cavity are the most serious, which can lead to anaphylactic shock and death in patients, and also produce secondary hydatid cysts in the abdominal cavity. If the daughter cysts break into the bile duct or hepatic vein, it can cause biliary obstruction and pulmonary artery embolism. Massive hemoptysis may occur. The amount of hemoptysis within 24 hours exceeds 600 to 800 ml or the amount of hemoptysis each time is more than 300 ml.

　　After the rupture of the hydatid cyst, toxic or allergic reactions often occur, and in severe cases, an anaphylactic shock may occur, leading to death. Local inflammatory swelling may occur. The exudation of the scolex in the cyst fluid can cause extracystic dissemination of infection, forming many new hydatid cysts nearby. Therefore, cyst puncture is absolutely contraindicated, and the wall of the cyst should be prevented from being stripped during surgery.

　　The incubation period of cystic echinococcosis is relatively long. It takes 10 to 20 years or even longer from infection to onset. The clinical manifestations mainly depend on the寄生部位 of the worm body, the size of the cyst, and whether there are complications. In the early stage of the disease, there are no自觉 symptoms, and the patient's overall health is good.

　　First, liver hydatid cyst

　　Most are located close to the surface of the liver, in the right lobe of the liver, so the main symptoms are a mass in the upper right abdomen or upper abdomen, but there will be no pain. Cysts are usually single, located on the diaphragmatic surface, protruding into the abdominal cavity, and can also be multiple. The surface is smooth, and the texture is relatively hard. The elevation of the diaphragm at the top of the right lobe of the liver is due to the upward growth of the hydatid cyst, which restricts movement. While hydatid cysts near the hepatic hilum may grow downward or compress the portal vein, causing portal hypertension; they can also compress the common bile duct, causing jaundice, mainly manifested as splenomegaly, varices of the lower segment of the esophagus, or ascites, but it is not common. In a few patients, the hydatid tremor can be felt during percussion. Patients with large hydatid cysts in the right lobe of the liver often have compensatory enlargement of the left lobe. The signs of hydatid cysts in the left lobe appear earlier and are more prominent.

　　The main complications of liver hydatid disease are infection and rupture, and the two often intersect, resulting in the following two outcomes:

　　1. The hydatid cyst in the liver has a very high internal pressure, and diagnostic puncture always causes the leakage of cyst fluid. The rupture of the hydatid cyst can be caused not only by compression but also by trauma. Large amounts of cyst fluid breaking into the abdominal or thoracic cavity can cause anaphylactic shock and cause the dissemination and transplantation of the headlets in the cyst fluid to the abdominal or thoracic cavity, resulting in multiple secondary hydatid cysts.

　　2. Bacterial infections from the bile duct can also be caused by trauma or puncture. Clinically, there may be fever, pain in the liver area, increased white blood cell count and neutrophils, resembling liver abscess. However, due to the relatively thick wall of the outer cyst, bacteria and toxins are not easily absorbed into the blood, so the toxicosis symptoms are relatively mild. Infection of hydatid cysts in the top of the right lobe of the liver, in addition to diaphragmatic elevation and movement obstruction, can also cause reactive pleuritis and effusion.

　　Two, Lung Hydatid Cysts

　　This disease has a relatively distinct trend: it is more common in the right lung and lower lobe, usually solitary, and multiple occurrences are rare. Early lung hydatid cysts are small, and patients have no自觉 symptoms, often found during chest X-ray examination. As the lung hydatid cyst gradually grows, symptoms such as chest pain, cough, sputum with blood, and persistent dull pain may occur. It can compress surrounding lung tissue, causing atelectasis and fibrosis. Some patients may have blood in their sputum, and occasionally massive hemoptysis may occur when the hydatid cyst ruptures. Some patients may have hydatid cysts penetrating into the bronchus, causing sudden paroxysmal coughing, difficulty breathing, expectoration of large amounts of watery cyst fluid and powdery corneal membranes, and hemoptysis. Occasionally, due to excessive leakage of cyst fluid and obstruction, asphyxia may occur. Infection may lead to symptoms such as fever and sputum with pus. A few cases may rupture into the pleural cavity, causing hydatid pleuritis.

　　Three, Brain Hydatid Cysts

　　It is more common in children and has a very low incidence, often found in the parietal lobe and usually accompanied by liver and lung hydatid disease. Clinical symptoms include headache, papilledema, and intracranial hypertension, with frequent seizures. Brain电图 can show focal slow waves. Cranial CT scans and magnetic resonance imaging can show large cystic shadows, which are of special contribution to localization and qualitative diagnosis.

　　Four, Orbital Hydatid Cysts

　　Hydatid disease of the orbit can occur at any part of the orbit, and its symptoms are similar to those of general orbital tumors, such as proptosis, deviation, and diplopia. Severe proptosis can lead to exposure keratitis, corneal ulceration, corneal perforation, and even panorbital inflammation or orbital atrophy. Some hydatid cysts can grow very large, filling the entire orbit, and can erode the orbital wall and invade the cranial cavity. They can also compress the optic nerve, causing papilledema, retinal hemorrhage, or optic nerve atrophy. Hydatids can occasionally be found in the eye, gradually growing in the vitreous body and leading to blindness.

　　5. Echinococcosis granulosa in other organs

　　Cystic echinococcosis can occur in abdominal and pelvic areas, spleen, kidney, brain, bone, mediastinum, heart, muscle, and skin, bladder, ovary, testis, and other sites. Alveolar echinococcosis can metastasize to lungs and brains, mainly presenting as compressive symptoms caused by loculated cysts, almost always accompanied by symptoms of liver or lung echinococcosis. There may be clinical symptoms and signs such as irritation or allergic reactions. A few patients may have simultaneous mixed infections of two species of echinococci. Some echinococcosis patients may develop parasitic embolism.

　　Improve the environment, cultivate good hygiene habits, wash hands before meals. Food should be cooked, do not drink raw water, do not eat raw milk, do not eat raw vegetables. Avoid close contact with dogs, especially important for children.

　　1. Health education and publicity on the serious harm of echinococcosis to humans and animals, the modes of infection, and the prevention and control measures.

　　2. Control the source of infection. Widely publicize the hazards of keeping dogs. Because dogs can not only spread echinococcosis but also transmit rabies, leishmaniasis, ascariasis, and other diseases. Wild dogs should be killed. Dogs that must be kept, such as sheep herding dogs and police dogs, should be registered and regularly quarantined. In areas where echinococcosis is prevalent, dogs should be regularly given anthelmintics such as praziquantel at a dose of 5mg/kg body weight, taken in one dose every 6 weeks. Dog feces should also be treated as harmless waste.

　　3. Do a good job of animal grazing and separate the dog pens from the sheep pens. Pay attention to feed hygiene and the cleanliness of animal shelters. Implement seasonal rotational grazing to reduce infection. Separate the water sources for humans and animals to prevent water source pollution.

　　4. Strictly implement veterinary health supervision and strengthen the meat inspection system. The internal organs of sick sheep should be buried deep or burned, or cooked before being used as feed for grazing dogs. Under no circumstances should the raw internal organs of sick sheep be fed to dogs.

　　Echinococcosis granulosa is a disease caused by the larvae of the small species of Echinococcus granulosus. Dogs are the definitive hosts, while sheep and cattle are intermediate hosts, so the disease is prevalent in pastoral areas. Humans can also become intermediate hosts if they accidentally ingest the eggs, leading to echinococcosis. So, what laboratory tests should be done for patients with echinococcosis granulosa? The following experts introduce the laboratory tests that should be done for echinococcosis granulosa:

　　1. Blood count

　　The white blood cell count is mostly normal. There is a slight increase in eosinophils. When there is secondary infection, the white blood cell count and the proportion of neutrophils increase.

　　2. Immunological examination

　　1. The hydatid antigen intradermal test uses 0.1 to 0.2ml of hydatid cyst fluid antigen from humans or sheep for intradermal injection. After 15 minutes, local papules become significantly larger with a surrounding erythema, and pseudopodia may appear (immediate reaction); 12 to 24 hours later, subcutaneous swelling and hard nodules follow. When there is an adequate amount of antibodies in the patient's blood, a delayed reaction often does not occur. In simple cases, both immediate and delayed reactions are positive. The immediate reaction remains positive after puncture, surgery, or infection; however, the delayed reaction is suppressed, and the intradermal test has a very high positive rate. False positives can occur and can be used as an initial screening in clinical practice.

　　2. Serum immunological tests The detection methods of serum antibody tests are various, including agar gel diffusion, latex agglutination, immunoelectrophoresis, indirect hemagglutination, and enzyme-linked immunosorbent assay (ELISA), enzyme-linked immunoelectrophoresis (EITB), etc. However, indirect hemagglutination and enzyme-linked adsorption are the most commonly used, with extremely high positivity rates. ELISA and EITB with high sensitivity and specificity can detect patients with low serum antibody levels. The positivity rate is highest for liver echinococcosis, with a high complement fixation test positivity rate, and only a few show false-positive reactions; the positivity rate of patients with multiple echinococcal cysts is higher than that of patients with single cysts.

　　3. Cyclic antigen determination This type of determination has low sensitivity and specificity, but it also has important diagnostic value. The application of monoclonal antibodies can improve its sensitivity and specificity. Double antibody sandwich ELISA is often used.

　　Three, Imaging examination

　　1. Ultrasound examination shows clear-edged round cysts within the liver, which can determine their location, size, and number. B-mode ultrasound examination has the advantages of being fast, non-invasive, and simple. Sometimes, it can be seen that the daughter cysts and the head nodules in the mother cyst are light spots. B-mode ultrasound examination is helpful for the popularization of echinococcosis in endemic areas, the positioning of echinococcal cysts before surgery, and the dynamic observation after surgery.

　　2. CT imaging examination provides reliable accurate positioning, size measurement, and counting of echinococcal cysts. CT imaging shows irregularly sized round or elliptical low-density shadows in liver and lung hydatid disease, with calcification in the cysts or on the cyst wall, and the low-density shadow edges show irregularly sized wheel-shaped round cyst shadows, indicating the presence of multiple daughter cysts inside the cyst.

　　3. X-ray examination shows that the X-ray chest film of pulmonary echinococcal cyst patients shows varying sizes, solitary or multiple round or elliptical shadows with clear edges and uniform density. The circular calcified shadow of the cyst wall on the abdominal X-ray film and the cystic shadow on the bone X-ray film are also of great significance for diagnosis.

　　4. MRI examination shows that the echinococcal cyst lesions show uniform low signal on T1-weighted images, high signal on T2-weighted images, and most of them show low signal on proton density images, with some showing equal signal. In the diagnosis of cystic echinococcosis, there is no more superiority compared to CT.

　　Because this disease is prevalent in pastoral areas, humans can also become intermediate hosts due to accidental ingestion of eggs, leading to echinococcosis. The disease is prevalent in pastoral areas, and humans can also become intermediate hosts by accidentally ingesting eggs. Foods should be cooked, do not drink unboiled water or milk, and do not eat raw vegetables. Avoid close contact with dogs, which is especially important for children. Strictly implement veterinary health supervision and strengthen meat inspection systems, manage the management of diseased animals' internal organs by deep burial, or incineration, or after boiling, and then used as feed for shepherd dogs. Prevent infection by the dog after eating. Avoid the contamination of water sources by eggs in dog feces.

　　Echinococcosis granulosa is a disease caused by the larvae of the small grain echinococcus tapeworm in humans, also known as cystic echinococcosis. Hydatid cysts are most common in the liver, followed by the lungs, and occasionally invade other organs such as the brain and bones. So, how is echinococcosis granulosa treated? Below, experts introduce the treatment methods for echinococcosis granulosa:

　　First, drug treatment

　　1. Albendazole: The duration of treatment should be based on the size of the hydatid cyst (follow-up by B-ultrasound scan), and it is advisable to take it continuously for one year or more. This drug has few and mild side effects. Long-term use has not shown significant damage to the liver, kidneys, heart, and hematopoietic organs. Occasionally, it can cause reversible leukopenia and transient elevation of serum alanine aminotransferase. Animal experiments with this drug have shown embryotoxicity and teratogenic effects, so pregnant women are prohibited from taking it.

　　2. Albendazole: Patients with cystic echinococcosis need to take medication for 1 to 6 months, and some patients with cystic echinococcosis can expect to be cured. The efficacy of albendazole for pulmonary echinococcosis is better than that for liver echinococcosis. Albendazole has poor absorption, and only 1% is absorbed when taken on an empty stomach. To improve efficacy, medication should be taken with a fatty meal, as the drug is easily absorbed along with fat. The absorption rate can be 5% to 20% when taken with a fatty meal.

　　Second, surgical treatment

　　PAIR method: Under CT guidance, percutaneous aspiration of the cyst fluid is performed, followed by the infusion of acanthocephalicide, and finally, it is aspirated again.

　　Before surgery, albendazole should be taken for treatment. The operation should first use a fine needle to aspirate the fluid from the cyst, then remove the inner capsule. The inner capsule and the outer capsule are only slightly adherent and easily剥离, and the excision operation should also be performed, using sit ametrole as the acanthocephalicide during the operation. The operation for the lung hydatid cyst also adopts the excision of the inner capsule. If the cyst is large and complicated with bronchiectasis, a lobectomy can be performed. It is not advisable to inject formaldehyde solution during the operation, as there is a possibility of concurrent sclerosing cholangitis. Both liver and lung hydatid cyst operations should prevent the excessive leakage of cyst fluid to avoid the occurrence of anaphylactic shock. Probenecid should be taken for 2 weeks before and 2 weeks after surgery to reduce complications during surgery and recurrence after surgery.