What Is Echinococcosis?

Echinococcus granulosus

Echinococcus granulosus (echinococcosis) is an animal-derived parasite with dogs as the terminal host. It is the main source of infection for the disease. Sheep are the main intermediate hosts, and cattle, horses, pigs, and camels can also be infected and become the source of infection. Infected people are mainly infected by accidentally eating insect eggs through the digestive tract. The parasites can be parasitic in the liver and throughout the body.

Echinococcus granulosus disease name

Echinococcus granulosus

Overview of Echinococcus granulosus disease

Echinococcus granulosus The patient had no obvious symptoms early in the clinic, and the course of the disease was long. In severe cases, allergic symptoms and weight loss appear. In patients with hepatic hydatid disease, the patient's right upper abdomen bulges, forming sacs, and he feels tremor upon palpation. When suffering from pulmonary echinococcus disease, the patient developed symptoms such as cough and hemoptysis.

Classification of Echinococcus granulosus disease

Gastroenterology

Description of Echinococcus granulosus disease

Echinococcus granulosus Echinccoccus granulosus (Batsch 1786) Rudphiphi, 1805] belongs to the genus Bandaceae and Echinococcus, also known as the cysticercus Pallas (1716). First noticed that human and animal echinococcus sacs are similar, Goeze (1782) First studied the Echinococcus sac with a microscope, and found the Ascaris head section, confirming that it is related to the head line of the band family, Hartman (1965) and subsequent Rudolphi (1808) studied the Echinococcus granulosus in the canine intestine, van Siebold (1853) used diseased internal organs of domestic animals, Naunyn (1863), and other scholars used human echinococcus to develop adults in the intestines of domestic dogs, and gradually understood the life history. Adults are parasitic in canine carnivorous animals, and larvae (echinococcus or hydatid) are parasitic in humans or other animals, causing echinococcus or hydatid disease. Echinococcus is widely distributed and is a zoonotic disease that seriously endangers human health and animal husbandry. In China, the disease is listed as one of the key parasitic diseases.

Morphology: Adult, this worm is one of the shortest species of tapeworm. The body is 2-7mm long and consists of a head section and a chain body. The chain has only one section of juvenile, juncture and pregnancy, and even one or more sections. The head section is slightly pear-shaped, with apical processes and 4 suction cups. The apical processes are rich in muscle tissue and have strong telescopic force. They have two loops of 28-48 hooks (usually 30-36). The top of the apical process consists of a group of spindle-shaped glands. The structure of the nodule is similar to that of the tapeworm. The reproductive pores are located in the middle of the nodule. There are 45-65 testicles distributed in the front and rear of the genital foramen. pregnant

Echinococcus foamy The node grows, and its reproductive pores open in the middle of one side of the segment. The uterus has irregular branches and lateral processes (also known as lateral sacs) and contains 200-800 worm eggs. Eggs are similar to pig and bovine tapeworm eggs, which are difficult to distinguish under light microscope. The larva, Echinococcus, is a circular sac-like body, the size of which varies depending on the time of parasitism, ministries, and hosts. The smaller one can be less than 1 cm in diameter and the larger one can contain about 2 L of cystic fluid within 40 cm. Echinococcus is a unilocular sac. It has a sac wall and its contents (germinal sac, source protozoa, ascus, grandson, and cyst fluid, etc.). The fibrous tissue surrounding the capsule wall has two layers surrounding the capsule wall. The outer layer is a corneal cortex with a thickness of about 1-4mm. It is milky white and translucent. It is powdery, crunchy, and easy to rupture. No cells are observed under light microscope. Structure is multi-textured. The inner layer is the germinal layer, also known as the germ layer, with a thickness of about 22-25m, with many cell nuclei. The germinal layer is closely attached to the horny cortex. It can be seen under the electron microscope that numerous hairs extend from the germinal layer into the horny cortex. The cavity is filled with liquid, called echinococcus fluid. The cyst fluid is colorless, transparent or slightly yellow, with a specific gravity of 1.01-1.02 and a pH of 6.7-7.8. It contains a variety of proteins, inositol, lecithin, urea, and a small amount of sugar, inorganic salts and enzymes, and has antigenicity. The germinal layer grows many protocephala (also known as protocephala) into the sac. The proboscis is oval or round, with a size of 170m × 122m. It is a head section that is rolled in and contracted. Its apical process and suction cup are invaded. Dozens of small hooks are protected, in addition, soda lime bodies can also be used. The difference between the proboscis and the adult head is its small size and lack of apical glands. The germinal sac, also known as the germinal sac, is a small sac with only one germinal layer. Nucleated cells from the germinal layer develop from it. It is observed that the germinal layer produces cells that form buds within the sac. These cells are hollow. Later, small capsules were formed and the small pedicles were connected with the germ layer, and 5-40 prototheciums of varying numbers were grown on the inner wall of the small capsule. In addition to growing into the hair follicles, the protothecium can also grow into the cyst exogenous protothecium. Due to its continuous expansion, its damage is further developed than that of the endogenous echinococcus. The structure of the ascus is similar to that of the mother. The cyst can also grow protozoa, hair follicles, and small sacs similar to the structure of the ascus, called cyst sand or echinococcus. There can be countless subprotozoites in a hydatid. Once ruptured and spread, many new hydatids can be formed in the intermediate host body. Some echinococcus sacs have no protozoon and hair follicles. Yu Bao.

Echinococcus granulosus symptoms and signs

The clinical manifestations of Echinococcus are extremely complicated, mainly including:

Toxic and allergic reactions

Such as loss of appetite, weight loss, weight loss, developmental disorders, cachexia, urticaria and echinococcus granulosus life history angioedema. If a large amount of echinococcus fluid exudates or overflows, it can cause severe allergic reactions and cause anaphylactic shock and even death.

Secondary infection

Such as rupture of the liver hydatid capsule can cause biliary tract today, causing acute inflammation, biliary colic, chills, fever, jaundice and so on. Breaking into the abdominal cavity can cause acute diffuse peritonitis. If the lung echinococcus sac ruptures into the bronchi, small hair follicles, ascites, and wall fragments can be coughed.

Local compression and irritation

There is slight pain and bloating in the affected area. Such as parasitic liver may have pain in the liver area. It can cause dry cough, hemoptysis, shortness of breath, chest pain and other symptoms in the lungs; brain involvement can cause symptoms such as increased intracranial pressure such as headache, nausea, vomiting, papilledema, convulsions and even hemiplegia. Bony echinococcus often occurs in the pelvis, the center of the vertebral body, and the metaphysis of long bones, destroying bone, making it loose, and easily causing fractures or bone fractures. Superficially located Echinococcus can form a mass on the surface of the body, which is tough and flexible, and may have tremors during percussion. A mass broken portal vein can cause ascites. If the bile duct is compressed, it can cause obstructive jaundice and cholecystitis.

Causes of Echinococcus granulosus disease

The final host of Echinococcus granulosus is canine, cricket, wolf and other canine families are meat animals, and the intermediate hosts are sheep, cattle, camels and other herbivores and humans. Adults parasitize in the upper part of the final host's small intestine. Small hooks and suckers on the apical process fixate the crypts in the base of the intestinal velvet. The pregnancy or worm eggs are discharged with the host's feces. It hatched in the intestine, drilled into the intestinal wall of Echinococcus granulosus, circulated to the liver and lungs and other organs through blood, and developed into Echinococcus with a diameter of 1-3cm after 3 to 5 months. Generally, the diameter of the sac can reach 0.5-1.0cm after half a year of infection, and it can grow by 1-5cm each year, and the maximum can grow to 30-40cm. Echinococcus can survive in the human body for 40 years, or even longer. At times, degeneration can occur. The sac fluid is cloudy and eventually absorbed and calcified. After echinococcus is swallowed by end hosts such as dogs and wolves, each protozoa contained in it can develop into a worm. Because echinococcus contains a large number of protozoa, the canine and wolf intestinal parasites can reach thousands. For tens of thousands, it takes 8 weeks from the infection to the maturity to discharge the eggs and pregnancy, and the adult life span is about 5-6 months.

Pathophysiology of Echinococcus granulosus

Echinococcus Echinococcus disease, known as hydatid disease, mainly caused by human damage and mechanical damage, children and young people are high-risk groups, about 80% of people under the age of 40, the severity depends on the health of Echinococcus in August Volume, quantity, parasitic time and location. After invading the host's tissues, the six-headed pheasant developed inflammatory responses and cell invasion around it, and gradually formed a slim outer capsule. Due to the slow growth of echinococcus, symptoms usually appear 5 to 20 years after infection. Primary echinococcus infections are mostly single. Secondary infections are often multiple, accounting for more than 20% of patients, and can affect several organs at the same time. Echinococcus can be found in almost all parts of the human body. According to the analysis of 15298 patients in Xinjiang, the most common part is the liver (69.9%). Mostly in the right lobe, the lungs (19.3%), and the abdominal cavity (3%) were the primary metastases from liver to various organs (5.3%). The other parts are: brain (0.4%), spleen (0.4%), pelvic cavity (0.3%), kidney (0.3%), thorax (0.2%), bone (0.2%), muscle (0.1%), gallbladder (0.1 %), Uterus (0.1%), and skin, eye-ovary, bladder, breast, thyroid, etc. (0.4%). Echinococcus grows faster in the lungs and spleen, and even causes atrophy of the lung lobe. Due to the continuous growth of echinococcus, it compresses surrounding tissues and organs, causing tissue atrophy and necrosis.

Echinococcus granulosus diagnosis test

Multilocular hydatid disease Echinococcus grows slowly, has no symptoms or signs for a long period of time, and its clinical manifestations are extremely complicated. It is difficult to diagnose early. Be alert to the possibility of the disease in endemic areas. First, you should ask your medical history to see if the patient is from an endemic area, and if you have a history of contact with animals such as dogs, sheep, or fur. Suspicious individuals can use physical diagnostic methods such as X-ray, B-mode, CT, MR (magnetic resonance) and isotope scanning, especially CT and MR. Not only can early diagnosis of asymptomatic carriers, but also accurately detect all Pathological images. However, these methods are difficult to make a clear diagnosis of the nature of the lesion. And some methods are more expensive, and the diagnosis should be based on the etiology results, such as surgical removal of echinococcus, or from sputum, pleural effusion, ascites or urine such as echinococcus fragments or protothecium. Serological experiments are commonly used as important methods of auxiliary diagnosis and epidemiological investigation. There are:

1. Casoni's batch test method is simple, the results can be obtained in 15 minutes, the positive rate is 78.6% -100%, but false positives (approximately 18% -67%) or false negatives are prone to occur. use.

2. Enzyme-linked immunosorbent assay (ELISA) is sensitive and specific, and kits are available for use.

3. The positive rate of indirect hemagglutination test (IHA) reached 80%, but the sensitivity was lower than that of ELISA.

4. The avidin-biotin-enzyme complex enzyme-linked immunosorbent assay (ABC-ELISA) sensitivity is the highest 4-6 times higher than conventional ELSA and few false positives.

5. Dot-ELISA is easy to operate and easy to observe. It is very suitable for grassroots use. In addition, there are still convergent immunoelectrophoresis (CIEP), indirect phosphor test (IFA), and latex agglutination test (LAT). Comprehensive methods should be adopted. Use 2-3 serology experiments to make up for each other's deficiencies to improve the accuracy of quasi-segmentation.

Echinococcus granulosus treatment options

Patients are generally treated with surgery, and surgery is required to avoid sac fluid overflow and prevent anaphylactic shock and secondary infection. Internal capsule excision and new residual cavity treatment methods have significantly improved the surgical cure rate. Early echinococcus can be tried with drugs such as albendazole, praziquantel, or xylidazole.

Prevention of Echinococcus granulosus disease

Comprehensive prevention and control measures should be adopted in endemic areas:

1. Strengthen health education and education, popularize hydatid disease knowledge, and develop good personal and dietary habits.

2. Strengthen the construction of sanitary regulations and sanitary quarantine, strengthen the human health code of conduct in accordance with the regulations, strictly and rationally treat sick animals and their internal organs, do not use them to feed dogs, strictly prohibit chaos, and promote deep burial or incineration.

3. Deworm insects for domestic dogs and collies on a regular basis. The Ministry of Health of China issued a new national plan for the prevention and treatment of hydatid disease in 1992. Health education, inspection and treatment of patients, training of professional and technical personnel, establishment of prevention and control institutions, regular prevention testing, scientific research on prevention and control, and strengthening of slaughter in endemic areas were introduced. Comprehensive health management and domestic dog registration and comprehensive control measures based on regular drug deworming and hunting of wild dogs. After several years of implementation, some areas have achieved some success, but there are still some issues that cannot be ignored in the prevention and control work. For example, insufficient attention has been paid to disease prevention and treatment, and funding is seriously inadequate. The coordination of the two major systems of health and agriculture and woodwork in prevention and treatment needs to be strengthened, and the instability of the prevention and research team needs to be resolved as soon as possible.

Echinococcus granulosus safety tips

Multilocular hydatid disease 1. The disease is caused by unclean diet, worm eggs in the food eaten into the body; coupled with inadequate diet, damage to the spleen and stomach, endogenous damp and heat, and caused the resident viscera to survive and reproduce and become ill.

2. The disease population is generally susceptible, and symptoms do not appear until puberty after childhood infection. Infected during childhood, 60% -70% of the total number of cases before the age of 20-40 years. Infection is more common in people under 40 years old, accounting for 80%.

1. Geographical distribution of Echinococcus granulosus hosts has a wide range of adaptability. In a certain natural environment, the final host and the intermediate host form a relatively fixed chain of official relations. According to this relationship chain, the epidemic can be divided into two types:

(1) Forest type (Arctic type), with no colder regions, mainly forming a wildlife cycle between dogs, wolves and deer;

(2) Animal husbandry type, which is widely distributed throughout the pastoral areas of all continents in the world. Domestic animal cycles are formed between canine and European artiodactyl livestock, including sheep / dogs, cattle / dogs, and pigs / dogs. The sheep / dog cycle is widely distributed, followed by the yak / dog cycle. It is found in the alpine meadows, foothills of the Tibetan Plateau and Gansu Province, and in the Tibetan areas of western Sichuan. Echinococcus granulosus and Echinococcus disease are distributed worldwide. The place where animal husbandry is developed is often the epidemic area of the disease, and it is endemic in Australia, New Zealand, Argentina, Uruguay, South Africa and Asia. In China, it is widespread in the northwest, north, northeast, and southwestern agricultural and pastoral areas, Xinjiang, Qinghai, Gansu, Ningxia, Tibet, Inner Mongolia, Shaanxi, Northwest, Shaanxi, Sichuan, Heilongjiang, Jilin, Liaoning, Henan, Shandong, Anhui, and Hubei. Epidemic or sporadic cases have been reported in 23 provinces (urban areas) including Guizhou and Yunnan. The prevalence of the population in endemic areas in the five provinces and districts of Northwest China is between 0.6% and 4.5%. The most susceptible people in the population are preschool children. Of the 15,289 patients in Xinjiang, 32.1% are under 15 years old. The main animal intermediate host Echinococcus infection rates in sheep range from 3.3% to 90%, and adult dog infection rates in domestic dogs range from 7% to 71%.

2. Epidemic factor

(1) The eggs pollute the external environment: the eggs have a strong resistance to the outside world, can withstand low temperatures to -56 degrees Celsius, can survive 11-12 days in a dry environment, and 7-16 days in room temperature water. Medicines also have strong resistance. Generally, chemical disinfectants cannot kill the eggs. On pregnancy, they have a strong ability to move. They can move along the plants in the grass, causing the eggs to pollute the surrounding environment, including pastures, barns, fur, and vegetables. Soil and water sources. Insect eggs can be spread with dogs and human activities and dust and feng shui in places where people and livestock are active. Dogs, cattle, sheep and other animals can also be infected with insect eggs.

(2) Infection methods of humans and animals: Herdsmen in endemic areas keep dogs to care for their animals, and children mostly like to play with domestic dogs; sick animals or their internal organs are mostly used to feed dogs or left in the wild, and dogs and wolves eat them at will. : Feces of sick dogs and wolves can easily contaminate pastures and water sources, causing the spread of the disease among animals. People in endemic areas have more contact with herd dogs or fur, and there are many opportunities for infection. Many People become infected by eating food, vegetables, fruits, water, or drinks contaminated by eggs. In non-endemic areas, humans become infected through occasional contact with infected dogs or with the skin of animals from endemic areas. With the rapid development of China's economy, a large number of livestock products in endemic areas have flowed to the inland. Therefore, there is also a potential epidemic danger in non-endemic areas.