Intestinal amebiasis

　　There are mainly four species of amebae parasitizing in the human colon, among which only Entamoeba histolytica is related to human diseases. Entamoeba histolytica has two species: one is the pathogenic strain of Entamoeba histolytica, and the other is the symbiotic strain of Entamoeba dispar. Although their morphology is the same, their antigenicity, genetic structure, and pathogenicity are completely different. The latter is a non-invasive ameba, non-pathogenic, and asymptomatic after infection; the former can cause invasive lesions, and human amebiasis is caused by the infection of the pathogenic strain of Entamoeba histolytica.

　　The life cycle of Entamoeba histolytica generally includes the cyst stage and the trophozoite stage. The cyst is the infectious stage of the ameba, while the trophozoite is the pathogenic stage. Cysts are found in the feces of chronic amebiasis patients or carriers, and the main route of human infection is through the ingestion of food and water contaminated with cysts.

　　并发症分肠内、肠外两大类：

　　一、肠内并发症

当肠粘膜溃疡深达肌层并侵及血管，可引起不同程度肠出血及肠穿孔，急性穿孔可发生弥漫性腹膜炎或腹腔脓肿。慢性穿孔较急性穿孔多见。腹部X线检查见膈下游离气体可确诊。亦可引起阑尾炎。阿米巴瘤(结肠肉芽肿)不见，为结肠壁慢性炎性增生反应，形成肉芽肿，可致肠套叠或肠梗阻。活检有助于诊断。

　　（1）肠出血：肠壁溃疡累及血管，可造成肠出血。出血量多少不等，大出血时患者往往出现面色苍白、脉搏细数及血压下降等出血性休克表现

　　（2）肠穿孔：多见于暴发型。穿孔部位以盲肠、阑尾及升结肠为多见。急性穿孔可引起弥漫性腹膜炎，病情严重。慢性穿孔造成周围组织粘连，形成局部脓肿。

　　（3）阑尾炎：阿米巴阑尾炎症状与普通阑尾炎相似，易形成脓肿，若有慢性腹泻或阿米巴痢疾病史，粪便中找到阿米巴滋养体或包囊，则有助于二者的鉴别诊断。

　　（4）非痢疾性结肠病变：系由增生性病变所引起，包括阿米巴瘤、肠道阿米巴性肉芽肿及纤维性狭窄。阿米巴瘤为大肠壁的炎性假瘤，以腹痛和大便习惯改变最多，部分伴间歇性痢疾，可诱发肠套叠和肠梗阻，主要体征为：右髂扪及可移动的、光滑的鹅卵形或肠曲样块物，X线上见占位性病变，对抗阿米巴治疗有良好效果。

　　二、肠外并发症

　　肠外并发症以肝脓肿最为多见，脓肿穿破可延及附近组织器官。经血路可直接累及脑、肺、睾丸、前列腺、卵巢等。

　　阿米巴肝脓肿(Amoebicliverabscess)可发生于本病全过程中，或者病后数周至数年。多以长期不规则发热起病，体温可达39℃以上，以弛张热型多见，常伴右上腹或右下胸部疼痛，肝脏进行性肿大，压痛显著为主要临床表现。脓肿多数为单发，且多在肝右叶，其原因多与右叶大，占整个肝脏体积的4/5，且肠道病变多在回盲部，该处大部血液循环经肠系膜上静脉流入肝右叶有关。肝脓肿若位于左叶，可在较短时间出现明显的局部症状与体征，但诊断较难。脓肿表浅可有局部压痛或具波动感，此时行肝穿刺见猪肝色、腥臭气味的脓汁，内含溶解坏死的肝细胞、红细胞、脂肪、夏科雷登结晶等，滋养体不多见，可在脓腔壁中找到，但未发现过包囊。若合并细菌感染，则脓腔内为黄绿色或黄白色脓液。

　　In chronic cases, fever is often not prominent, and symptoms such as weight loss, anemia, malnutrition edema may occur. The peripheral blood count shows that the total white blood cell count is often increased in the early stage and can decrease to normal in the later stage. The positivity rate of parasites in the stool examination is not high. At this time, trophozoites can be seen in the bile of the duodenal drainage C tube.

　　Liver function tests show that most transaminases are normal, serum cholinesterase is reduced, and alkaline phosphatase is slightly elevated. X-ray examination shows elevation and restriction of the right diaphragm, with local bulging of diagnostic significance. When there is a left lobe abscess, the barium meal examination shows compression of the lesser curvature of the stomach and leftward displacement of the gastric body. B-ultrasound, isotope liver scanning, CT scanning, and MRI can all help with diagnosis.

　　Amoebic lung abscess often occurs secondary to liver abscess, with symptoms similar to bacterial lung abscess and bronchiectasis. If bronchopleural fistula occurs, a large amount of coffee-colored pus may be coughed up. If pleurisy occurs, there may be pleural effusion, and if it appears as coffee-colored, it is helpful for diagnosis. Amoebic pericarditis is rare and can be caused by the penetration of an amebic liver abscess in the left lobe into the pericardium. The symptoms are similar to those of bacterial pericarditis and are the most dangerous complications of the disease.

　　Amoebic dysentery can present with intestinal and extra-intestinal complications.

　　Extra-intestinal complications: Amoebic trophozoites can spread from the intestines through blood and lymph to distant organs, causing various extra-intestinal complications, such as liver, lung, pleura, pericardium, brain, peritoneum, and urogenital tract, forming abscesses or ulcers, among which liver abscesses are the most common.

　　The incubation period is on average 1-2 weeks (4 days to several months), with different types of clinical manifestations.

　　1. Asymptomatic type (cyst carriers) This type often does not present clinical symptoms, and amebic cysts are found during multiple fecal examinations.

　　2. The common type has a slow onset, with mild systemic symptoms of poisoning, often without fever, mild abdominal pain, diarrhea, with more than 10 bowel movements per day, moderate in amount, with blood and mucus, mixed evenly with necrotic tissue to form a jam-like consistency, with a foul, putrid smell, containing piles of amebic trophozoites and a large number of red blood cells, which is one of its characteristics. The lesion site may have a feeling of urgency and tenesmus. Tenderness in the abdomen is mainly on the right side. These symptoms can be self-resolved. They may also recur due to incomplete treatment.

　　3. The mild type is seen in individuals with stronger physique, with mild symptoms, such as 3-5 loose or watery stools per day, or alternating diarrhea and constipation, or no diarrhea, just feeling discomfort or hidden pain in the lower abdomen, with occasional mucus or a small amount of blood in the stool, and the cysts and trophozoites of the disease can be detected. There are no complications, and the prognosis is good.

　　4. The fulminant type is extremely rare, and it can occur due to severe infection with the pathogen, concurrent bacterial enteritis, or weakened physique, presenting as a fulminant type. The onset is acute, with obvious symptoms of poisoning, including aversion to cold, high fever, delirium, toxic enteroplegia, and severe abdominal pain with tenesmus, frequent diarrhea up to dozens of times a day, even incontinence, with feces resembling bloodwater, wash meat water, or thin water, which is very similar to acute bacillary dysentery, but characterized by its peculiar smell containing a large number of active amebic trophozoites. There is marked tenderness in the abdomen. Complications such as peripheral circulatory disorders due to dehydration, or accompanied by consciousness disorders, may occur, even intestinal hemorrhage, intestinal perforation, peritonitis, etc., with poor prognosis. The course of the disease is generally 1-2 weeks. The mortality rate reaches over 50%.

　　5. Chronic type often causes alternating diarrhea and constipation due to improper treatment during the acute phase, causing recurrent clinical symptoms, lasting for more than 2 months or several years without cure. It often recurs due to colds, fatigue, poor diet, etc. Patients often feel abdominal distension and pain, and over time, they may experience fatigue, anemia, and malnutrition. The right lower abdomen may feel thickened colon with mild tenderness; the liver may swell with tenderness. Feces may contain pus and blood, trophozoites, and sometimes cysts.

　　6. Other types of amebiasis can cause infections in the urinary tract, reproductive system, skin, etc., but they are rare. They can also start with complications and are easily misdiagnosed.

　　The prevention of this disease is basically the same as that of bacillary dysentery. Completely treat patients and carriers. Vigorously eliminate flies and cockroaches. Pay attention to drinking water and food hygiene, strengthen fecal management, and prevent fecal contamination of food and water.

　　1. Hygiene of food and drinks at home

　　Do not eat the food from the previous day, as it is easy for food to spoil and bacteria to grow in hot weather. Open fruits like watermelons should be eaten as much as possible, and if not finished, they can be sealed with a保鲜膜 and stored in the refrigerator, but not for more than 24 hours. Foods must be fully heated and boiled before eating, and drinking water also needs to be boiled before drinking. It is necessary to cultivate the habit of washing hands frequently for babies, and let them know that the nail缝 is the easiest place to hide dirt, and pay special attention to cleanliness when washing hands. Do not eat your hands in everyday life.

　　2. Hygiene of food and drinks when traveling

　　When traveling, try to bring your own food and water, or dine at regular restaurants or designated restaurants by travel agencies. Wash cold dishes, blanch them with boiling water, mix them with vinegar, ginger, and garlic, and then eat them. Try to order fewer or no cold dishes. Some foods that are prone to carry pathogenic bacteria, such as snails, shellfish, and crabs, should be thoroughly cooked and steamed before eating, and bad eating habits such as direct consumption after vinegar pickling or salting should be avoided. Do not eat unfamiliar foods or other potentially toxic foods such as mushrooms.

　　The prognosis of amebic dysentery is generally good, related to the duration of the disease, the presence of complications, whether early diagnosis and timely effective treatment are made. Patients with fulminant type, cerebral metastatic abscess, intestinal perforation, and diffuse peritonitis have a poorer prognosis.

　　1. Examination: ① Routine fecal examination, pay attention to find the amoebic dysentery ameba trophozoites and cysts. ② Blood routine. ③ If necessary, send fecal culture for Shigella and amoebic dysentery amebas, once upon admission and once the next morning, to see if there is mixed infection.

　　2. Special examinations should be conducted with sigmoidoscopy before and after the treatment of chronic cases, and the specimens should be scraped to examine for amoebic dysentery amebas. When there is suspicion of concurrent amoeboma or intestinal polyps, or suspected inflammatory bowel disease, intestinal tuberculosis, colon cancer, and other diseases, fiberoptic colonoscopy and biopsy or intestinal barium X-ray examination should be performed.

　　3. Suspected cases should be selectively sent for specific immunological examination of the amoebic dysentery ameba according to the conditions.

　　4. Diagnostic treatment for suspected cases can use antiamoebic drugs for diagnostic treatment.

　　1.Amebic dysentery food therapy recipes

　　Recipe One

　　Medicines: Flesh of wild plum 20-30 grams, ginger 5-10 grams, green tea leaves 3-5 grams, appropriate amount of brown sugar.

　　Usage: Crush the flesh of the wild plum, cut the ginger into thin strips. Put the flesh of the wild plum, ginger, and green tea leaves into the pot, boil for 5 minutes, and mix in brown sugar. Take 1 dose a day, divided into 2 doses, taken warm.

　　Indications: Used as an adjuvant treatment for amebic dysentery and bacterial dysentery.

　　Recipe Two

　　Medicines: Saururus chinensis (without lotus root) 25 grams, Liquorice root 6 grams,芍药 6 grams.

　　Usage: Put the herbs such as Saururus chinensis, Liquorice root, and芍药 into a pot, add an appropriate amount of water and boil, then remove the dregs and drink the juice. Take 1 dose a day, divided into 2 doses.

　　Indications: Used as an adjuvant treatment for amebic dysentery.

　　2. Food therapy remedies:

　　1. Green tea leaves 30g, pour a bowl of boiling water to extract the flavor, take 2 to 3 times a day.

　　2. Fungus 5g, brown sugar 60g, add half a bowl of water, boil with the dregs, take 1 time a day or in 2 doses.

　　3. Daylily 30g, brown sugar 60g, scalded and cooked, take 1 time a day or in 2 doses.

　　4. Fresh portulaca 60g, crushed, add 4 bowls of water and appropriate amount of brown sugar, boil to 3 bowls, take 1 bowl each time, 3 times a day.

　　3. Simple remedies:

　　Goose bile: remove the shell and take the kernel, 15-20 grains per dose for adults, 3 times a day; in capsules, taken after meals. A course of treatment is 7-10 days. Goose bile has a killing effect on amebic trophozoites and the根治 rate for amebic dysentery is 50%.

　　1. General treatment:Pay attention to rest and eat semisolid, low residue, high-protein diet.

　　2. Pathogen treatment:Metronidazole, also known as Metronidazole: Originally an antiprotozoal drug, it has a strong killing effect on amebic trophozoites that invade tissues and is relatively safe, suitable for all types of amebiasis in and outside the intestines. The dosage is 600-800mg, taken orally, 3 times a day, for 5-10 consecutive days; for children, 50mg/kg/day, taken in 3 doses, for 7 consecutive days. Nausea, abdominal pain, dizziness, and palpitations may occur occasionally during the medication period, and no special treatment is required. Avoid alcohol during the medication period, as it may cause mental confusion. It is禁忌 for pregnant women within 3 months and lactating women.