Hydatid disease

Introduction to echinococcosis Hydatidosis, or echinococciosis, is a chronic parasitic disease caused by human larvae of the echinococcosis (Echinococcus). Epidemiological surveys in recent years have shown that endemic parasitic diseases; characterized by occupational damage in endemic areas, are classified as occupational diseases in certain populations; on a global scale, echinococcosis is a minority or religious tribe A common disease and frequently-occurring disease. basic knowledge The proportion of sickness: 0.01% Susceptible people: no specific population Mode of infection: digestive tract spread Complications: abdominal pain jaundice

Cause of echinococcosis

[pathogen]

Hydatidosis is a disease caused by the larvae of Genus echinococcus. The currently recognized insect species are Echinococcus granulosus, E. multilocularis. E. vogeli Rausch, E. oligarthrus, has slightly different morphology, host and distribution areas, and is most common with Echinococcus granulosus.

Echinococcus granulosus is only 1.5 to 6 mm long and consists of a head section and 3 individual sections. Adults are parasitic in the small intestine of dogs, but wild animals such as wolves, foxes, and pelicans can also be their final hosts. There is a double-layered embryonic membrane, which has a similar morphology to that of the aphid, and is more resistant to the outside world. When the eggs are excreted with dog feces, contaminated pastures, barns, vegetables, soil and drinking water, by people or sheep, etc. After the intermediate host swallows, it enters the duodenum through the stomach. After the action of the digestive juice, the six hooks are shelled out, drilled into the intestinal wall, and enter the portal vein system with blood circulation. Most of the larvae are blocked in the liver and develop into a package. Insect sac (Echinococcus sinensis); part of it can escape to the lungs or through the lungs and spread throughout the body to develop the echinococcal sac. After the dog swallows the viscera of the sheep or other intermediate host containing the hydatid sac, the original scorpion Entering the intestinal crypt of the small intestine and developing into an adult (about 7-8 weeks) to complete its life history, the terminal host of Echinococcus multilocularis is mainly fox and dog, and the larvae (both ball python) are mainly parasitic in the middle. Host the rodent or the liver of the human body.

The disease is globally distributed, mainly in animal husbandry areas. In China, Gansu, Ningxia, Qinghai, Xinjiang, Inner Mongolia, Tibet, western Sichuan, and Shaanxi are common, and there are scattered cases in Hebei and Northeast China.

Infection (45%):

The main source of infection of this disease is dogs, wolves, foxes, baboons, etc. Although it is also the final host, it is of little significance as a source of infection. There are often echinococcosis in the flocks of endemic areas, and residents often use sheep or other Feeding the dog's internal organs, the dog has the opportunity to swallow the hydatid cyst, the infection is often more serious, the number of intestinal parasites can reach hundreds to thousands, and the pregnancy section has the ability to move on the fur and cause the anus. Itching, when the dog bites, the segment is crushed, and the eggs in the feces often contaminate the whole body fur, and if it is in close contact with it, it is easily infected.

The infection is mainly caused by close contact with the dog. The infected egg on the fur coat contaminates the finger and is infected by the mouth. If the egg in the dog dung contaminates the vegetable or water source, especially the same water source, the human and animal can also cause indirect infection. In the dry and windy area, Eggs flutter in the wind, and there is also the possibility of infection through the respiratory tract.

Bad living habits (10%):

Human infection is mainly related to environmental sanitation and poor health habits. The number of patients is mostly peasants and herders. The brothers are far more than the Han nationality. Because the hydatid sac grows slowly, it is usually infected in childhood, and obvious symptoms appear in young adulthood. There was no significant difference in the incidence of men and women.

Hydatidosis prevention

The echinococcosis is a zoonotic disease. The intermediate host includes livestock and wild animals. Its prevention is not only a complex problem in the biological field, but also a serious social problem. Comprehensive measures should be taken, including:

(1) Strengthening the handling and control of dogs in the epidemic areas: cattle are the key link to prevent human echinococcosis infection. Wild dogs should be extinct in the epidemic areas of the worms, and the dogs must be strictly restricted. For the must-have shepherd dogs, hounds or police dogs Such registration must be listed, regular locust mites and drug monitoring should be classified as a regular system. According to New Zealand's report on severe epidemic areas, the drug is driven once every 6 weeks, and the mildly endemic area is changed to 3 months.

(2) Vigorously carry out health education: the means of education can be diversified, the content should be simple and easy to understand, and practical, and the masses should be fully mobilized to make them well-known and well-known.

Complications of echinococcosis Complications, abdominal pain, jaundice

Often the first symptom of a patient's visit, the main complications are:

1 cyst perforation: liver hydatid cyst can be broken due to trauma or puncture, can be misdiagnosed as acute abdomen when broken into the abdominal cavity, severe abdominal pain with shock, followed by allergic symptoms, therefore, liver puncture in patients with hepatic hydatid disease should It is regarded as a strict contraindication. The pressure in the cystic cavity of the hydatid is very high. After the puncture, not only the leakage of the cystic fluid, anaphylactic shock, but also the original head lice can be planted in the abdominal cavity to produce a secondary hydatid cyst. Into the liver bile duct, broken capsules cause obstruction of the bile duct, each causing biliary colic and jaundice.

2 infection: about 1/5 ~ 1/4 liver hydatid cysts have secondary infections, infections are mostly from the biliary tract, lung hydatid cysts are also common, infection can promote the death of the worm, but it also significantly aggravates the condition.

Symptoms of echinococcosis common symptoms hemoptysis

Echinococcus is growing continuously, causing extrusion of parasitic organs and adjacent tissues and organs, causing tissue cells to shrink and necrosis. There is a slight pain and a feeling of bulging in the affected area. Such as parasitic in the liver may have liver pain, in the lungs may have shortness of breath, chest pain and other respiratory irritation symptoms, involving the brain can cause epilepsy and headache, vomiting and other symptoms of increased intracranial pressure, parasitic bones easily cause fractures.

Hydatidosis check

(1) Blood: Eosinophilia is seen in half of the cases, generally not more than 10%, and even up to 70%. After the hydatid cyst is ruptured or after surgery, the eosinophils in the blood are significantly increased.

(2) Intradermal test: The inside of the forearm was injected with 0.1 ml of cystic fluid antigen, and the reaction was observed after 15 to 20 minutes. The positive part showed red papules, which may have pseudopods (immediate reaction), and disappeared after 2 to 2 1/2 hours. About 12 to 24 hours followed by redness and induration (delayed reaction). When there is a sufficient amount of antibody in the blood of the patient, the delayed reaction often does not occur. In simple cases, both immediate and delayed reactions are positive, in the puncture, Immediately after surgery or infection, the response is still positive, but the delayed response is inhibited. The positive rate of intradermal test is between 80% and 90%, but false positives may occur, and other parasitic diseases, especially with tsutsugamushi disease, are higher. Non-specific reactions, cross-reactivity can also be seen in malignant tumors, abdominal tuberculosis.

(3) Serum test: Serum immunological test is used to detect serum antibody in patients. There are many test methods, but indirect hemagglutination test and enzyme-linked adsorption are most commonly used. The positive rate is about 90%, and false negative or false positive can also occur. Response, the positive rate of serum immunological test of pulmonary cystic echinococcosis is lower than that of hepatic cystic echinococcosis, the positive rate of complement fixation test is 80%, and about 5% is false positive reaction (this disease and trematode and cysticercosis) There is a cross-immunization phenomenon, and other latex agglutination, immunofluorescence test, can be selected according to the specific circumstances.

(4) Image diagnosis: including X-ray examination, ultrasound examination, CT and radionuclide scanning examination, etc. Although these examinations are important means for diagnosing echinococcosis, they should be combined and comprehensively analyzed when judging the results. It is helpful for diagnosis. For example, the chest radiograph can help locate the echinococcosis. The liver echinococcosis shows a circular or elliptical low-density shadow of different sizes on the liver CT. Calcification can occur in the cyst or the wall of the cyst. The edge of the low-density shadow shows a round-shaped cystic sac of different sizes, suggesting that there are multiple ascosons in the capsule. B-mode ultrasound examination is helpful for the spread of echinococcosis in the epidemic area, and the hydatid cyst before surgery. Positioning and dynamic observation after surgery.

Diagnosis and identification of echinococcosis

The clinical manifestations of this disease vary depending on the location, size and complications of the hydatid cyst. For a long time, hydatid disease is considered to be a parasitic disease of human beings (animals), which is called animal-derived disease.

The disease should be differentiated from non-parasitic benign cysts, liver abscesses, mesenteric cysts, giant hydronephrosis, lung abscesses, tuberculoma balls, brain tumors, bone tumors, etc. According to the characteristics of various diseases, it is not difficult to make a diagnosis.

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