Amoebic dysentery

Overview amoebic dysentery (amebic dysentery). also known as amoebiasis (intestinal amebiasis). by pathogenic E. histolytica parasite penetrated the colon wall dysentery caused by the symptoms of gastrointestinal diseases. Lesions more Ileocecum and easy to relapse into chronic. Protozoa can flow from the wall by-lymphatic movement or directly to the liver, lung, brain and other organs become parenteral amoeba disease, Amebic liver abscess particularly the most common. Amebic dysentery pathogen (E. histolytica. Amoeba histolytica) as the only human pathogenic amoeba. in human tissues and faeces trophozoites are big, small cysts and trophozoites three forms. Trophozoites in vitro resistance weak and easy to death. Encapsulation strong resistance to the outside world. (1) trophozoites large trophozoites 20-40μm size, relying on a certain pseudo-foot move Acute found in the faeces of patients with intestinal tissue or swallow and erythrocyte, it is also called tissue-type trophozoites. Trophozoites small size 6 ~ 20μm, pseudo-foot small to host intestinal fluid, bacteria, fungi to eat, phagoerythrocytic. also known as enteric-trophozoites. When host declining health, the organization dissolved enzyme secretion, in addition to their own campaign invasive intestinal submucosa, into a major trophozoites; When intestinal adverse change in the conditions of their activities into early cyst, and then into cysts. Trophozoites in the dissemination of no significance. (2) encapsulation more common in subclinical infection and stool of patients with chronic, was circular, 5 ~ 20μm size, mature cyst has four nuclear, E. histolytica infection type, is contagious. Encapsulation more resistant to the outside world in the faeces of the survival of at least two weeks, the water five weeks, the refrigerator 2 months, resistant to chemical disinfectants strong tolerance to 0.2% permanganate few days, ordinary drinking water disinfection with chlorine concentration without killing its role, but the heat (50 ° C) and dry very sensitive. E. histolytica need for the cultivation of bacteria, which occur symbiosis. Symbiosis currently no training has been successful for pure antigen preparation and in-depth study E. histolytica provided the conditions. Epidemiology of chronic patients, and patients with cystic convalescent carriers of the disease is the main source of infection. Through contaminated water, vegetables, fruits, food and other gastrointestinal dissemination, but also through contaminated hands, supplies flies. cockroaches and other indirect oral transmission. Susceptible ordinary crowd, after infection not have immunity (that is not protective antibody), is therefore vulnerable to re-infection. Of the disease around the globe, more common in tropical and subtropical regions. China was particularly prevalent in the north. Incidence rate in rural than in urban; Men than women, adults than children, most of the distribution, Even by factors such as water pollution and the outbreak. Pathogenesis and pathological changes amoeba cysts enter the digestive tract, in the lower intestine was trypsin digestion and other digestive fluid, capsule to escape from the body, and repeatedly split the small trophozoites form a majority, to live in the cecum and colon, and other parts trophozoites health host small stool with depression, and sigmoid colon were the following excreted into cyst is not pathogenic. Under proper conditions, such as gastrointestinal function lower body; Free for certain bacterial gene-like factor, increase the virulence trophoblast; trophozoites release of lysosomal enzyme, hyaluronidase, proteolytic enzymes and rely on its pseudo-foot mechanical activities, invasive intestinal undermine small abscess formation and submarine-shaped (beaker brief) ulcers, caused widespread damage organization can reach deep myometrial, trophozoites with necrosis material from intestinal and blood discharge, showing dysentery-like symptoms. Changes in chronic diseases, epithelial hyperplasia, the bottom of ulcer formation of granulation tissue, ulcers around fiber hypertrophy, Formation amoebiasis. Trophozoites vein wall can be accessed by the portal or lymphatic vessels to the liver, caused small hepatic vein thrombosis and around Yan, liver necrosis and liver abscess in the right lobe to be. And can peg their way into the lung, brain, migratory abscess formation. Intestinal trophozoites or directly spread and the surrounding tissue, rectovaginal fistula formation of the skin or mucosa with various diseases. Individual cases can cause intestinal bleeding, intestinal perforation with peritonitis, or, Lan Mei Yan. Can be seen under the microscope as its major tissue necrosis disease, a small number of lymphocytes and neutrophils infiltration. If serious bacterial infection, was acute diffuse inflammatory changes, the more inflammatory cell infiltration and edema, necrosis. Visibility lesion site of a number of Acanthamoeba trophozoites, mostly gathered in the marginal parts of ulcers.