Entamoebiasis histolytica
Introduction
Introduction to E. histolytica E. histolytica is a pathogen of invasive amebiasis, mainly parasitic in the colon, causing amoebic dysentery and various types of amebiasis. It is globally distributed and is more common in tropical and subtropical regions. The cause of the disease is mainly whether small trophozoites can invade tissues and cause lesions. It is determined by various factors, including: 1. Changes in host physiology, such as malnutrition, infection, intestinal dysfunction, intestinal mucosal damage Etc., resulting in reduced host resistance; 2. Synergistic action of suitable bacterial species (bacteria can provide amoeba growth, suitable physical and chemical conditions for reproduction), promote amoeba proliferation, and can directly damage the host intestinal mucosa, Conducive to the invasion of amoeba, enhance its virulence and so on. basic knowledge The proportion of illness: 0.002% Susceptible people: no special people Mode of infection: fecal mouth pathway Complications: enteritis
Cause
Etiology of amebic disease
Cause:
Whether small trophozoites can invade tissues and cause lesions are determined by various factors, including: 1. Changes in host physiology, such as malnutrition, infection, intestinal dysfunction, intestinal mucosal damage, etc., causing host resistance Reduce; 2. Under the synergy of suitable bacterial species (bacteria can provide amoeba growth, suitable physical and chemical conditions for reproduction), promote the proliferation of amoeba, and directly damage the intestinal mucosa of the host, which is beneficial to the invasion of amoeba. To enhance its virulence and so on.
Prevention
Prevention of amebic disease in the tissue
The amebic amebic disease is mainly caused by the contamination of water, food, vegetables, etc. into the human intestine by amoeba. The disease is easy to recurrent, and its symptoms are different. Therefore, patients with chronic diarrhea or ambiguous intestinal diseases should consider this disease. The disease is easy to be complicated by intestinal bleeding, intestinal perforation, appendicitis, colitis, liver abscess and other intestinal and external complications, should be vigilant. For patients with chronic diarrhea who are not treated with simple antibiotics, anti-amebic drugs are often used to receive unexpected effects.
1. Treat patients and worms to control the source of infection. In particular, discover and treat cyst carriers and chronic patients who are engaged in diet work. If necessary, identify the species and determine the treatment strategy.
2. Manage feces and protect water sources as the main link in cutting off the transmission route of amebiasis. It is a key measure to prevent amebiasis by treating the manure in a harmless manner according to local conditions, killing the cysts, and strictly preventing the feces from contaminating the water source.
3, pay attention to food and drinking water sanitation, develop good personal habits, eliminate pests, do a good job of environmental sanitation, prevent disease from mouth, are all powerful measures to protect susceptible population.
Complication
Complications of amebic disease Complications enteritis
In rare cases, liver abscess can penetrate into the pericardium and penetrate the abdominal wall. The intestinal amoeba can also enter the perianal, vaginal, urethra and other areas of the abscess or inflammation caused by the corresponding parts. Common complications include enteritis and amoebic swelling. Amoebic appendicitis and so on.
Symptom
Symptoms of amebic disease in the tissue. Common symptoms, bloating, dysentery, relaxation, heat, urgency, hepatomegaly, progressive weight loss, brain abscess
The clinical manifestations of amebiasis are often changed, often prolonged, that is, the course of disease is prolonged, and the symptoms are impermanent. According to the clinical classification recommended by WHO, it can be divided into asymptomatic infection and symptomatic invasive infection. More than 90%, most of the infections of non-invasive species in the complex, the latter divided into intestinal inflammation (including amoebic dysentery, enteritis, amoebic, amoebic appendicitis, etc.) and intestine Exobia disease (including amoebic liver, lung, brain abscess and cutaneous amebiasis), the typical amoebic dysentery is often accompanied by abdominal cramps and urgency, heavy, with pus and blood sugar Abdominal dysentery is rare.
Most of them manifest as subacute or chronic protracted enteritis, which may be accompanied by abdominal distension, weight loss, anemia, etc. Intestinal amebiasis is most common with amebic liver abscess, which is disseminated by blood, which occurs in the right lobe of the liver. History of intestinal amoebia, mostly slow onset, relaxation heat, hepatomegaly, liver pain and progressive weight loss, anemia and nutritional edema, amoebic lung abscess is rare, liver-borne and intestinal Source, the former is caused by the direct perforation of the amoebic liver abscess; the posterior yarn blood transmission, the lesion is not limited to the right lower lobe, in rare cases, the liver abscess can penetrate the pericardium, wear the abdominal wall, the intestinal amoeba Can also enter the perianal, vaginal, urethra and other areas caused by abscess or inflammation, common complications are enteritis, amoebic, amoebic appendicitis.
Examine
Examination of amebic disease in dissolved tissue
1. Pathogen examination:
(1) stool examination:
1) saline smear method: suitable for pus and bloody stools of patients with acute dysentery or amebic enteritis, mainly to check the trophozoites of the activity, but the specimens must be fresh, the faster the inspection, the better, set 4 ° C should not exceed 4 ~5 hours, the typical amoebic dysentery stool is a red mucus-like sauce, which has a scent. The microscopic examination shows that there are many sticky red blood cells and fewer white blood cells in the mucus, and sometimes the Charcot-Leyden crystal and Active trophozoites, these characteristics can be distinguished from the stool of bacterial dysentery.
2) Encapsulation concentration method: For the formed fecal samples of chronic patients, the smear period can also be used to find the encapsulation period, often used for iodine staining to show the nucleus, which is convenient for differential diagnosis, but the encapsulation examination can be improved by concentration method. The rate of extraction, commonly used methods are zinc sulfate floatation and mercury iodide centrifugal precipitation (MIFC, detailed appendix).
Clinically common atypically persistent amebiasis, it is often difficult to find pathogens in the feces. According to analysis, asymptomatic patients or lesions are confined to the cecum and ascending colon, routine wet smear or fixed stain smear The outflow rate is not more than 30%, and the positive rate can be increased to 60-80%, and the rate of sending 5 times can reach more than 90%.
(2) Artificial culture: There are a variety of improved culture media available (see Appendix). The diagnostic routine for the isolation and culture of worms from fecal specimens is cultured with bacteria, but the detection rate in most subacute or chronic cases is generally not High, so the culture method seems to be not suitable for routine inspection, no special culture medium and technical requirements for co-biological culture, should be used for research.
(3) Tissue examination: direct observation of mucosal ulcers by sigmoidoscopy or fiberoptic colonoscopy and biopsy or scraping smear detection rate is the highest, about 85% of patients with dysentery can be detected by this method, living specimens must be taken from the edge of the ulcer, Puncture puncture should also be taken from the wall, and pay attention to pus traits.
The pathogen examination should pay special attention to the cleansing of the container and the influence of the patient's medication and treatment measures. Some antibiotics, insecticides, laxatives, astringents, high, hypotonic enema, barium meal and self-urine pollution can cause the trophozoite to die. Interfere with the detection of pathogens.
2. Immunodiagnosis
Because the pathogen diagnosis of amebiasis is easy to miss and misdiagnosis, immunological diagnosis is an indirect auxiliary method, but it has great practical value. Since the 1960s, amoeba has no co-culture and specific monoclonal antibody. After the advent of the world, it provided the amoeba pure antigen and high-quality tool antibodies in the lysate. Various immunodiagnostic methods have been developed at home and abroad. In recent years, various improved methods of enzyme-linked immunosorbent assay (ELISA) have been applied. The detection rate of specific circulating antibodies can be as high as 95% to 100% in patients with liver abscess, 85% to 95% in patients with invasive enteropathy, and only 10% to 40% in asymptomatic carriers. The titer depends on the condition. Can be inconsistent, but the majority of abscesses are high titers, so serological diagnosis only has a large auxiliary diagnostic value for patients with acute disease. In serum epidemiological investigation, the growth and decline of antibody titer in the population may indicate the incidence of the disease in the area. The application of monoclonal antibody and DNA probe hybridization technology provides a specific, sensitive and anti-interference tracer for detecting pathogens in host blood and excretion, using monoclonal antibodies to detect feces. , Pus insect antigens and DNA probes to identify the species of insects in the feces have been to see the report.
Diagnosis
Diagnosis and identification of amebic disease in dissolved tissue
Diagnosis based on pathogen examination. This disease should be distinguished from bacterial dysentery.
