Echinococcosis/Hydatid Disease-What is echinococcosis?
Echinococcosis, or hydatid disease (echinococciosis) is due to people infected with the larvae of Echinococcus (hydatid cyst) of chronic parasitic diseases.The clinical manifestations of hydatid disease as the hydatid cyst location, size and without complications a long time, hydatid disease is considered to be the beast of a man (animal) suffering from parasitic diseases, known as zoonotic disease butepidemiological surveys show that in recent years, commonly known as endemic parasitic diseases; in endemic areas with the characteristics of occupational injury, occupational disease as a certain population groups; echinococcosis as minority or religious communities, speaking from the worldwideunique to a common and frequently-occurring disease.
Echinococcosis/Hydatid disease - the cause ofPack echinococcosis etiologyHydatid disease is Echinococcus genus the (Genus echinococcus) disease caused by larvae of the insect species are currently recognized parasite Echinococcus the Ying worm (Echinococcus granulosus), multi-room Echinococcus (E. multilocularis), V s Echinococcus (E. Vogeli Rausch) a small section of Echinococcus (E. oligarthrus). Slightly different morphology, host and geographical distribution of Echinococcus granulosus is the most common.
The Echinococcus long only 1.5 ~ 6mm from a first section and three individual section. Adult parasites in the small intestine of the dog, wolf fox, jackals and other wild animals can also be its definitive host. The eggs were round double embryo membrane form of Taenia eggs resistant eggs with dog feces, pollution ranch, barn vegetables, soil and water, or sheep, to the outside world other intermediate host is swallowed by the stomach into the room duodenum. The Oncosphere shelling out the role of the digestive juices, drill into the intestinal wall into the portal vein with the blood circulation system, and larvae of most resistance to develop into hydatid cyst (Echinococcus granulosus) in the liver; part can escape to the lungs or pulmonary hydatid cyst scattered development in body organs. Dog devouring the internal organs of sheep or other intermediate hosts containing hydatid, the former head larva into the small intestine within the intestinal crypts develop into adults (about 7 to 8 weeks) to complete its life history more than Echinococcus terminal host to a fox, dog, larvae (including hydatid) parasitic in the intermediate host rodents or human liver
Echinococcosis/Hydatid disease - pathogenesis(A) of hydatid disease - the source of infection of this disease is the main source of infection for dogs, wolves, foxes, jackals, etc. Although the definitive host, but of little significance as a source of infection. Often the presence of hydatid disease in the flock of the endemic areas, residents often sheep or other livestock offal, feed the dog, the dog swallowed the opportunity to hydatid infection often more serious, the number of intestinal parasites can reach several hundred to several one thousand of their pregnancy section of film activity, you can climb in the fur and cause anal itching dog lick bite proglottis crushed, feces, eggs often contamination of the body fur, such as their close contacts have great vulnerability to infection .
(B) of hydatid disease - the route of transmission of direct infection is mainly due to close contact with the dog after oral infection of the eggs contaminated fingers in their fur. If the dog eggs contaminated vegetables or water, particularly humans and animals drink from the same water can also result in indirect infection. In arid areas, eggs fluttered also the possibility of infection through the respiratory tract.
(C) of hydatid disease - susceptibility to infection and environmental sanitation and poor hygiene practices in patients with farmers and herders, other ethnic groups than the Han more. Growth is slow in general for hydatid infection in childhood to young adults of obvious symptoms. No significant difference in the incidence of men and women.
Echinococcosis/Hydatid disease - signs and symptomsThe diagnosis is based on the following three points:
(A) epidemiological data of the disease found in pastoral areas Most patients with a history of close contact with dogs, sheep and other.
(B) in patients with clinical signs of the above, if any relief from abdominal painless mass (tough, smooth, cystic), or cough, hemoptysis and other symptoms should be suspected of the disease and for X-ray, ultrasound, CT and radionuclide Check to make and establish the diagnosis
(C) laboratory tests intradermal test sensitivity but poor specificity, serology immunoelectrophoresis, enzyme-linked immunosorbent assay with higher sensitivity and specificity, but specificity and sensitivity in addition to a variety of immunodiagnostic its own characteristics, subject to all antigens, methods of operation, the positive standard intradermal test for serum response, and patients with hydatid cyst location, and infection period of time after surgery and the individual immune response, such as factors
Echinococcosis/Hydatid disease - examination testsLife history of multiple Echinococcus (a) blood eosinophils increase seen in half of cases is generally not more than 10%, even up to 70%. Hydatid cyst rupture or post-operative blood eosinophils for each significantly increased the phenomenon.Fluid antigen (b) intradermal test capsule 0.1ml injection inside of the forearm after 15 to 20 minutes to observe the reaction, the positive local red papules, pseudopodia (immediate reaction) to subside after 2 to 21/2 hours, about 12 to 24 hours followed by swelling and induration (delayed reaction). When there are sufficient quantities of antibodies in the blood of patients with delayed response often does not appear. In simple cases, the immediate response and delayed response showed a positive immediate reaction was still positive after the puncture, surgery, or infection, but delayed response was inhibited intradermal test was positive in 80% to 90%. But false positives can occur, other parasitic diseases, especially with taeniasis and other higher non-specific reaction, the cross-reactions can also be found in malignant tumors, abdominal tuberculosis.
(C) serum test serological test to detect a variety of patient serum antibody test methods, but the most commonly used indirect hemagglutination test and enzyme adsorption, the positive rate of about 90% can also be false negative or false positive reactions. The lungs of cystic hydatid disease serological test positive rate lower than the liver cystic echinococcosis. Complement fixation test was positive in 80%, about 5% were false-positive reactions (cross immunity between the disease and the trematodes and cysticercosis). Others are still latex agglutination, depending on the particular circumstances of the immunofluorescence test selection.
(D) images of diagnostic X-ray ultrasound, CT and radionuclide scans, and the above checks are diagnosis an important means of hydatid disease, but in the judgment of the results should be combined with each other and to conduct a comprehensive analysis will help in the diagnosis. Sizes round or oval low density, such as chest X-ray helps the positioning of the pulmonary hydatid disease of liver hydatid disease by the liver on CT, the cyst wall may be calcified, low density edge of the display wheel-shaped circular cyst shadow of varying sizes suggest the capsule there is more than one ascus. B-mode ultrasound examination can help the popularity of hydatid disease in endemic areas, hydatid cyst in the pre-operative positioning and dynamic observation after surgery.
Echinococcosis/Hydatid disease - complicationsOften the first symptom in patients with treatment complications:① cyst puncture: hepatic hydatid cyst rupture due to trauma or puncture. Ruptured into the abdominal cavity can be misdiagnosed as acute abdomen, severe abdominal pain and shock was followed by allergic symptoms, liver biopsy in patients with hepatic hydatid disease should be considered a strict contraindication hydatid cysts within the pressure very high puncture not only occurrence of the cyst fluid leakage, anaphylactic shock and enable the former head larva grown in the abdominal cavity and secondary hydatid cyst. Cyst breaking hepatic bile duct, the broken capsule skin caused by bile duct obstruction resulting in biliary colic and jaundice.② infection: about 1/5 ~ 1/4 liver hydatid cyst with secondary infection, infection from the the biliary lung hydatid cyst complicated by infection is quite common. The infection can contribute to the the hydatid death, but also significantly aggravate the condition.
Echinococcosis/Hydatid disease - drug treatmentThe preferred method of surgical cure of this disease should strive for the purposes of compression symptoms or complications. First surgery when a thin needle to the cyst fluid and drain (beware of cyst fluid spills), then the internal capsule removal of the internal capsule and external capsule only mild adhesion, easy to peel, you can often remove the lung, brain, bone and other parts of hydatid disease should be OK surgery for the removal
Surgical removal of hydatid sac before the hydatid capsule into 10% formalin solution to help kill the larva of the original head, as the products of lung tissue irritation and occasional side effects of poisoning, it is especially NA ruptured lung or liver hydatid cyst abroad, West song bromide (cetrimide) to kill the former head larva, and that is of low toxicity, the effect of a good ideal to kill the former head larva agent for human hydatid cyst excision, sub- 2 injected into the capsule of the right amount of 0.1% Cetrimide, each lasted five minutes, a group of 10-year period 378 cases of surgical applications and post-operative observation reports indicate that, no cases of hydatid recurrence, but not with Cetrimide before postoperative package insects recurrence rate was 10%.
Views according to the WHO, albendazole and mebendazole are classified as a drug of choice for anti-hydatid authors believe that the indications are as follows: the ① secondary abdominal or thoracic hydatid disease occurred in the primary liver or lung sac echinococcosis complicated by rupture, can also be protected due to hydatid surgery lax or mistaken for diagnostic puncture, resulting in hydatid cyst fluid to leak out, the proliferation of secondary cultivation lesions throughout the whole abdominal cavity or chest surgery is difficult to eradicate. ② multiple or multi-organ cystic echinococcosis or recurrent hydatid disease, the patient is unwilling or difficult to accept again (more) operations. The ③ sick old and infirm, or the coexistence of organic disease of important organs surgery poor tolerance. ④ by surgical exploration or no cure for advanced liver alveolar hydatid disease, or secondary lung and brain metastasis, and drug treatment can relieve symptoms and prolong survival ⑤ whether cystic or alveolar echinococcosis before and after chemotherapy as a surgical adjuvant, can reduce the relapse rate to improve the outcome.
After the advent of benzene up to azole in the treatment of hydatid disease replaced mebendazole, albendazole absorption is better, the serum concentrations of mebendazole 100 times hydatid cyst fluid concentration than mebendazole 60 times. To the treatment of cystic hydatid disease, the dose of daily 10 ~ 40mg/kg 2 times service 30 days for a course, the visual condition for several courses of treatment is superior to mebendazole, especially in pulmonary hydatid disease Jia. Alveolar echinococcosis domestic, it was suggested that long-term large-dose albendazole treatment the daily dose of 20mg/kg treatment from 17 months to 66 months (average 36 months) range, by the long-term follow-up found CT scan showed significant progress, all in most cases, the original lesions calcification have been recovered, the effective rate of 91.7% of patients on long-term treatment can be tolerated, no serious side effects, but the rule Cheng Zhongyi follow-up liver and kidney function and bone marrow. Pregnant women hanged.
Echinococcosis/Hydatid disease - prevention and health care
Echinococcosis echinococcosis human zoonotic diseases, intermediate hosts, including domestic and wild animals, their prevention is not only the biological context of a complex issue, but also a serious social problem should adopt comprehensive measures, including:
(A) to strengthen the key endemic area of dog handling and control of cattle for the prevention of human hydatid infection in wild dogs of the hydatid endemic areas should be extinct, the dog is severely restricted, will shepherd hound or dogs must be listed registration. The regular taeniafuge and drug monitoring should be classified as a conventional system, and changed to three months dosing once every 6 weeks of dosing, according to the provisions of New Zealand reported severe endemic areas drive the sash once mild endemic areas.
(B) strict meat hygiene inspection of meat processing factory or slaughterhouse meat must earnestly implement the health and quarantine sick animals, liver, lungs and other organs infected with hydatid must be properly activation centralized incineration, digging deep, liquid poison such as France should not feed the dog.
