chronic amebiasis enteritis
Introduction
Introduction to chronic amebic disease enteritis Amoebic enteropathy is an intestinal infection caused by parasitic amoeba in the colon (proximal colon and cecum). It is often called amoeba because of clinical symptoms such as abdominal pain, diarrhea, and urgency after urgency. Dysentery. Atypical manifestations include amoebic enteritis, amoebic tumors, amebic appendicitis, or even fulminant colitis. The disease has many recurrences and is easy to turn chronic. basic knowledge The proportion of illness: 0.95% Susceptible people: no special people Mode of transmission: mouth communication Complications: appendicitis ulcerative colitis intestinal obstruction amoebic liver abscess
Cause
Chronic amebiasis enteritis
1, the cause of the disease
In recent years, it has been reported that some of the amoeba in the lysate are not pathogenic and can survive in some people's intestines for a long time without causing symptoms. The non-virulent insect strain has a surface antigen component different from the pathogenic strain, and does not produce a proteolytic enzyme, and the corresponding antibody is not produced in the host blood.
2, the pathogenesis
The lytic amoeba has two different forms of trophozoites and cysts in its life history. After the capsule is ingested by humans, it can pass through the upper part of the stomach and small intestine without damage, and is trypsinized into the lower part of the small intestine. It has a mature capsule of 4 nucleus and can be deflated to become a small trophozoite (diameter 7-20 m). Parasitic in the intestine cavity, taking bacteria as food, does not damage the intestinal wall tissue, and both split and multiply, and grow well in the anaerobic part of hypoxia. When the body's resistance is insufficient or the local intestinal mucosa is damaged, the small trophozoites can become large trophozoites (20-40 m in diameter), which can secrete lysozyme to destroy intestinal wall tissue, invade intestinal mucosa and submucosa, and multiply and form. Localized submucosal abscess, mainly necrotizing substance, ruptured abscess, forming a bottle-like ulcer. The mucosa between the ulcer and the ulcer is basically normal, which is obviously different from bacterial dysentery. When the body's resistance is enhanced, the large trophozoites can become small trophozoites, and can be further transformed into capsules (about 10 m in diameter), which are excreted with the feces. It can survive for 2 to 4 weeks in a cool and humid environment, and can live for 6 to 7 weeks in a refrigerator, but it is not heat-resistant, and it will die at 50 ° C for 5 minutes. Only 4 nuclear mature capsules are contagious, and 1 to 2 nuclear immature capsules are not contagious, but in a suitable external environment, they can develop into 4 nuclear capsules. The size of the trophozoites, such as excreted, quickly died. If the course of disease is prolonged, the destruction of intestinal wall tissue and connective tissue hyperplasia can be carried out at the same time, which can cause hypertrophy of the intestinal wall, narrowing of the intestinal lumen, and occasionally forming an "ameaboma" due to excessive proliferation of connective tissue.
Prevention
Chronic amebiasis enteritis prevention
1. Thoroughly treat patients and insects.
2. Vigorously eliminate flies and cockroaches.
3. Pay attention to drinking water and food hygiene, strengthen manure management, and prevent feces from contaminating food and water.
Complication
Chronic amebiasis enteritis complications Complications appendicitis ulcerative colitis intestinal obstruction amoebic liver abscess
Chronic patients can develop anemia and malnutrition. In addition, intestinal wall tissue is subject to different damages in the acute and chronic phase, which can cause the following complications.
1, intestinal perforation caused by peritonitis Tsang reported 254 cases of amoebic disease, surgery and autopsy proved that there were 19 cases of intestinal perforation, 7.48%. Adams reported that 95 out of 3013 patients developed peritonitis (3.2%), although the incidence was not high, but the prognosis was poor.
2. Amoebic appendicitis Clark reported that 40% of the 186 cases of amoebic patients had appendicitis. Criag reported that 26.67% of 60 patients had appendicitis. The incidence is indeed high. Therefore, in areas with high incidence of amebiasis, many acute abdomen are caused by amebic appendicitis or permeation of the amoebic appendix.
3, intestinal stenosis chronic amebic colitis patients, intestinal wall tissue hyperplasia, hypertrophy and amoebic granuloma formation, leading to stenosis. A small number of patients even develop intestinal obstruction and require surgery.
4. Of the 3013 patients reported by Amoeba Adams, 15 had amoebic tumors (0.5%).
5, non-specific ulcerative colitis amoeba has been completely eliminated, converted into non-specific ulcerative colitis. In Adams' statistics, there were 21 cases (0.7%).
In addition, intestinal bleeding, intestinal polyps and intussusception are rare.
Symptom
Chronic amebiasis, symptoms of intestinal inflammation, common symptoms, abdominal pain, diarrhea, urgency, heavy weight
The incubation period of amoebic colitis varies from 1 to 2 weeks or more. Different clinical manifestations may occur due to the number of cysts ingested, the virulence, and the strength of the body's resistance.
1, asymptomatic: mainly refers to those who are carriers of amoeba, more than the census found that these people are often ignored by patients because of mild symptoms. Maanshan City Epidemic Prevention Station reported that 22.7% of 1166 cases of amoeba positive were asymptomatic. These patients are important sources of infection for this disease.
2, amoebic enteritis: similar to common enteritis, patients may have abdominal pain and diarrhea, feces are not formed or loose stools, mixed with mucus and undigested food, the smell is greater.
3, amoebic dysentery: similar to bacterial dysentery, but the symptoms of poisoning are lighter. The patient can have fever of about 38 °C, abdominal pain, diarrhea, several times a day to more than 10 times. The stool is bloody mucus, or the stool is separated from the blood, and sometimes it is completely bloody. If the number is small, the stool is dark red or jam-like, stinking.
Carefully look for the amoeba in the patient's fresh stool, especially in the bloody mucus, and once the active phagocytic amoebic trophozoite with red blood cells is found, the diagnosis can be confirmed. Once found, it should be repeated several times and strive to do bacteria and amoebic culture. Attention should be paid to thermal preservation during microscopy, otherwise the amoebic trophozoites are inactive and are not easily distinguished from macrophages. Sigmoidoscopy is helpful for diagnosis, especially for differential diagnosis. In the acute phase, the flask-like ulcer can be seen, and the mucosa between the ulcers is normal. In the chronic phase, hyperplasia of the intestinal mucosa, granuloma and polyps can be seen. The pathological examination can be performed on the lesion to obtain the pathological examination to further determine its nature.
Examine
Chronic amebiasis enteritis examination
Fecal examination is an important basis for diagnosis. It is still necessary to identify non-pathogenic amoeba protozoa after pathogens are found. At present, serological examination is developing rapidly, and it is a key experiment for diagnosing amebiasis. About 90% of the patients' serum can detect different titers of antibodies by ELISA, indirect hemagglutination and indirect immunofluorescence. PCR diagnostic techniques are very effective, sensitive and specific methods.
The WHO Special Committee recommended that the cysts containing quadruplex should be detected by microscopy and should be identified as E. histolytica or Despana amoeba. The trophozoites containing red blood cells should be detected in the feces and should be highly suspected to be dissolved in the tissue. Miba; serological examination of high titer positive, should be highly suspected to be E. histolytica infection. Amoebiasis is caused only by E. histolytica.
1. Colonoscopy has not obtained positive results in those microscopy, serology and PCR tests, but in clinically highly suspected cases, colonoscopy or fiberoptic colonoscopy is feasible. In about 2/3 of the symptomatic cases, the rectum and sigmoid colon mucosa showed scattered ulcers of different sizes. The surface was covered with yellow pus, the edges were slightly protruding, slightly congested, and the mucosa between the ulcer and the ulcer was normal. Scrape the material from the ulcer surface for microscopic examination and found that there are more opportunities for trophozoites.
2, X-ray barium enema examination of the lesions have filling defects, paralysis and congestion. Although this finding is not specific, it contributes to the identification of amoebic and intestinal cancer.
Diagnosis
Diagnosis and diagnosis of chronic amebic disease enteritis
1, epidemiology: more incidence in autumn, mostly for dissemination. Patients often have unclean eating habits or close contact with chronic patients.
2, clinical features: the disease is more slowly, the course of disease is longer, and there is a tendency to recurrent.
(1) Acute amoebic dysentery:
Typical: systemic symptoms are mild, no fever or low fever, diarrhea is more than 10 times a day, the amount of feces is medium, often with mucus and blood, typical of a hazel-like appearance, and stench. There is tenderness in the right lower quadrant. Heavy or light after no hassle.
Light weight: only mild abdominal pain and loose stools.
The fulminant hair: anxious fever, obvious toxemia. The stools are more than 20 times a day, mostly bloody or gravy-like, with heavy and obvious abdominal tenderness, and complicated with intestinal bleeding or intestinal perforation.
(2) Chronic amoebic dysentery: When the symptoms of dysentery occur, the time is heavier, lighter and heavier, or abdominal pain, bloating, alternating constipation and diarrhea, which lasts for several months or years. Long-term illnesses are malnutrition and anemia.
3, laboratory inspection
1 fecal microscopy: visible clusters of red blood cells and a few white blood cells. Find a dissolved tissue amoeba trophozoite can be diagnosed. It is helpful to diagnose the amoebic encapsulation in the chronic phase.
2 amoebic culture or serological examination: conditional, can do amoeba culture or serological examination, such as: complement binding test, indirect hemagglutination, indirect immunofluorescence, ELISA, etc.
3 colonoscopy: there are scattered buttonhole-like ulcers on the normal mucosa, scraping its contents to check the amebic trophozoites, the positive rate is higher. In addition to ulcers in chronic patients, mucosal thickening and polyp formation can be seen.
