amoebic dysentery
Introduction
Introduction to amoebic dysentery Amoebicsentery is a disease caused by the parasitic tissue of entamoebahistolytica, which is often referred to as intestinal amebiasis or amoebic colitis. It can also be extended from the intestine to other organs or directly to adjacent tissues, especially the liver, to become an abscess. The incubation period is generally 1 to 2 weeks, which can be as short as 4 days and as long as 1 year or more. basic knowledge The proportion of the disease: the disease is an infectious disease, the incidence rate is 0.02% - 0.04% Susceptible people: no specific people Mode of infection: fecal mouth spread Complications: peritonitis liver abscess
Cause
Amoebic disease
Infection factor (35%):
The E. histolytica has two phases of trophozoites and cysts. The trophozoites have been divided into small trophozoites and large trophozoites. The former is parasitic in the intestinal lumen, which is called the intestinal commensal trophozoite. Under the influence, it can invade the intestinal wall, and the phagocytic red blood cells are transformed into the latter, which is called tissue trophozoite. In recent years, molecular taxonomic studies have confirmed that the genotypes and phenotypes of the two types of insect strains have distinct specificities. Therefore, it is believed that most of the trophozoites in the intestinal lumen are the trophozoites of the Despana amoeba, which are intestine commensal organisms and do not invade the intestinal wall, and the trophozoites of the amoeba in the lytic tissue have the size regardless of their size. Invasive.
Dietary factors (30%):
Since the food or drinking water is contaminated by the pathogen capsule, after the capsule is swallowed, the capsule enters the lower part of the small intestine, the trophozoites escape from the sac, and the feces are dropped, parasitizing the intestinal cavity of the cecum, colon, rectum, etc. Feeding bacteria and superficial epithelial cells in the intestine, under the influence of various factors, the trophozoite invades the intestinal mucosa and causes ulcers. When it reaches a certain extent and extent, it causes dysentery. It is generally considered that the amoeba in the tissue is dissolved. Among the pathogenic factors.
Prevention
Amoebic dysentery prevention
Boiling, filtering, disinfecting drinking water, preventing eating lettuce and preventing contamination of the diet, proper handling of feces, prevention of flies and fly killing are important measures. It is extremely important to check and treat sacs and chronic patients in the catering industry. At home, the food is hygienic. Don't eat the food on the day. The heat is easy to make the food spoil and the bacteria grow easily. Open fruits, such as watermelon, should be eaten as much as possible. If you can't finish it, you can use a plastic wrap and put it in the refrigerator, but the time should not exceed 24 hours. When you are traveling, try to bring your own food and water, or go to a regular restaurant or travel agency to dine at a restaurant. Wash your cold salad and boil it with boiling water. Add vinegar, ginger and garlic and mix well. Try to keep less or not. dish.
Complication
Amoebic dysentery complications Complications, peritonitis, liver abscess
Intestinal complication
(1) Intestinal hemorrhage: Deep ulcers can erode blood vessels and cause intestinal bleeding of varying degrees. Sometimes it becomes the main symptom of this disease, and a large amount of bleeding is rare.
(2) Intestinal perforation: mostly occurs in patients with fulminant and deep ulcers. The perforation is common in the cecum, appendix and ascending colon. Perforation can cause localized or diffuse peritonitis. Acute perforation is rare. Chronic perforation More, most of them have no severe abdominal pain. The time of perforation is often difficult to determine, but the general condition is gradually worsened. X-ray examination can be confirmed by free gas. Sometimes, due to the formation of adhesion, a local abscess can be formed after perforation, or penetrate into the vicinity. Organs form internal hemorrhoids.
(3) Amoebic appendicitis: cecal lesions easily spread to the appendix. The clinical symptoms are similar to those of general appendicitis, but they are prone to perforation. It is said that in the tropical and subtropical regions due to appendicitis, about 1/3 are amoeba. Caused by infection.
(4) colon granuloma: chronic cases due to mucosal hyperplasia, granuloma, the formation of large lumps, very similar to tumors, known as amoebia, easily misdiagnosed as intestinal cancer, more common in the cecum, sigmoid colon and rectum.
2. Extraintestinal complications
The amoeba trophozoite can be spread from the intestinal wall vein, lymphatic vessels or directly to the liver, abdominal cavity, lung, pleura, pericardium, brain, genitourinary tract or adjacent skin, forming an abscess or ulcer. Miba liver abscess is most common.
Symptom
Amoebic dysentery symptoms Common symptoms Intestinal perforation mucus cough chocolate color diarrhea abdominal pain fatigue low fever stool abnormal urgency after abdominal discomfort
The incubation period is generally 1 to 2 weeks, which can be as short as 4 days and as long as more than 1 year. The onset is sudden or hidden, and the following clinical types are available.
1. Asymptomatic (protozoan carrying status): Amoeba protozoa can be found in most feces without symptoms. The cysts are only found in routine fecal tests and are excreted throughout the infection, as co-habiters, non-invasive tissues About 90% of these patients are infected with Despan's amoeba, but there are also very few infections with E. histolytica. The symptoms are not obvious. For many years, subclinical conditions such as abdominal discomfort, bloating, constipation, etc. have been maintained.
2. Ordinary type: usually slow onset, abdominal discomfort, thin stool, sometimes diarrhea, several times a day, sometimes constipation, diarrhea, stool, slightly pus, dysentery, such as lesion development, dysentery can increase To 10 to 15 times / d or more, accompanied by urgency and weight, abdominal pain and abdominal distension, ileocecal, transverse colon and rectum can have tenderness, systemic symptoms are mild, often low fever or no fever, the above symptoms generally last for several days In a few weeks, it can be relieved by itself. If it is not treated, it is easy to relapse. The fecal examination may have a small amount or a large amount of trophozoites.
3. fulminant: This type is rare, mostly occurs in frail and malnourished, rapid onset, significant symptoms of poisoning, severe illness, high fever and extreme exhaustion, stool rapidly increased to 15 times / d or more, including obvious pus With a large number of nourishing bodies, even anal incontinence, watery or bloody, with strange smell, accompanied by vomiting, severe abdominal pain, urgency and weight and obvious tenderness in the abdomen, patients with varying degrees of dehydration and electrolyte imbalance, sometimes shock, easy to enter the intestine Bleeding and intestinal perforation, if not actively rescued, can die from toxemia or complications within 1 to 2 weeks.
4. Chronic type: often the continuation of the common type without thorough treatment, the course of disease can last for months or even years, the diarrhea recurrent, or alternate with constipation, the general diarrhea does not exceed 3 to 5 times a day, the stool is yellow Paste, with a small amount of mucus and blood, rancid, often accompanied by pain in the umbilical or lower abdomen, symptoms may persist, or intermittent, intermittent periods vary, may be weeks or months, no symptoms during the interval Frequently due to fatigue, improper diet, overeating and emotional changes are the causes of recurrence, long-term patients are often accompanied by anemia, fatigue, weight loss, liver and neurasthenia, easy to have appendicitis and liver abscess, stool examination can be found Tronus or cysts.
The diagnosis of typical amoebic dysentery is not difficult. The diagnosis depends on the pathogens found in the feces. Atypical cases often require colonoscopy, serological examination and diagnostic treatment.
Examine
Amoebic dysentery
1. Fecal examination: For the important basis of diagnosis, the feces of typical amoebic dysentery are dark red jam-like, with special odor, more faecal, blood and mucus, and a large amount of red blood cells and a small amount of mucus. White blood cells, it is said that two kinds of E. histolytica can be identified directly from fecal PCR.
2. Serological examination: the application of amoeba pure antigen can be used for a variety of immunological serological diagnostic tests. The asymptomatic cysts are negative for antibody detection. Recombinant antigen detection antibodies have been used, and their sensitivity and specificity are reported. More than 90%.
3. Nucleic acid detection: mainly extract pus or fecal culture, biopsy intestinal tissue and pus and blood, and carry out amplification reaction with appropriate primers. It is considered that the molecular weight of Amoeba in the tissue is 29×103/30. The primers designed for the 103 polycysteine antigen (also known as peroxiredoxin) have the best specificity and sensitivity.
4. X-ray barium enema examination: the filling part has filling defects, sputum and congestion.
Diagnosis
Amoebic dysentery diagnosis
Diagnostic criteria
Clinical symptoms
Generally, the onset is slower, the symptoms of poisoning are lighter, the number of diarrhea-like diarrhea is less, there is jam-like stool, and it is easy to recurrent. Because of its different symptoms and lack of characteristics, it is chronic diarrhea or ambiguous bowel. Patients with diseases should consider the possibility of this disease.
2. Laboratory examination
Fecal examination is an important basis for the diagnosis. After the pathogen is found, the non-pathogenic amoeba must be identified. The serological examination is developing rapidly. It is a key test for the diagnosis of amebiasis. About 90% of the patients have serum. The antibodies can be detected by ELISA, indirect hemagglutination and indirect immunofluorescence. The PCR diagnostic technique is a very effective, sensitive and specific method. The WHO Special Committee recommends that the cysts containing quadruplex be detected under the microscope and should be identified as E. histolytica or dippanemideba; detection of trophoblasts containing red blood cells in feces should be highly suspected to be E. histolytica; serological examination of high titer positive, should be highly suspected to be dissolved in tissue Amoebic infection, amebic disease caused only by E. histolytica.
3. Colonoscopy
For those microscopic examinations, serological and PCR tests did not yield positive results, and clinically highly suspected cases, feasible colonoscopy or fiberoptic colonoscopy, about 2 / 3 of the symptomatic cases, rectal and sigmoid mucosa visible size The scattered ulcers, the surface is covered with yellow pus, the edge is slightly protruding, slightly congested, the mucosa between the ulcer and the ulcer is normal, and the material is scraped from the ulcer surface for microscopic examination, and the chance of trophozoite is more.
4. X-ray barium enema examination
There are filling defects, sputum and congestion in the lesions. Although this finding is not specific, it is helpful for the identification of amoebic and intestinal cancer.
5. Diagnostic treatment
If there is a high degree of clinical suspicion and various examinations can not be diagnosed, anti-amebic drugs can be used. If the effect is correct, the diagnosis can be established.
Differential diagnosis
Bacterial dysentery
2. Schistosomiasis: history of contact with infected water, liver and spleen, increased blood eosinophils, hatching of fecal hair follicles, rectal mucosal biopsy eggs and ring egg sedimentation test or circulating antigen test can be identified.
3. Colon cancer: generally older, bowel habits change and have a sense of sorrow, feces become thin and blood, there is progressive abdominal distension, anal finger examination, X-ray tincture, colonoscopy, etc. to help identify.
4. Non-specific ulcerative colitis: left sacral pain, endoscopic examination showed extensive congestion of the colonic mucosa, edema, ulcers and bleeding, multiple pathogen tests negative, serum immunological test amoebic antibody negative, anti-A Diagnosis can be made if the diagnostic treatment of Miba is ineffective.
