Schistosomiasis japonica

　　The size of the adult schistosomes in intercalated schistosomiasis varies with the host and is prone to confusion with other species of schistosomes. The males are 11.5-14.5mm long and 0.3-0.5mm wide; the testes are 2-7 in number, most of which are 4, with small spines on the ventral, lateral, and dorsal sides, starting from behind the testes, with small nodules on the epidermis; the females are 13-24mm long and 0.2-0.25mm wide. The ovaries are located between the intestinal branches and are mostly coiled. The eggs in the uterus are on average 140μm×37μm, with about 25%-60% of the eggs starting to lay after 80 days of infection, with the maximum number of eggs laid by each worm being 122. The egg end has spines, slightly curved, and the eggshell is acid-fast positive.

　　Intercalated schistosomiasis can cause liver fibrosis and intestinal complications. The specific complications are as follows:

　　1. Liver fibrosis complications
　　More than 2/3 of advanced patients have complications such as varices in the lower esophagus or the fundus of the stomach. The incidence of massive upper gastrointestinal bleeding caused by rupture of varices is 16.5% to 31.6%, which is the main complication of schistosomal liver fibrosis. Clinical symptoms include massive hematemesis and melena, which can lead to hypotension and hemorrhagic shock, with a mortality rate of about 15%. About half of the patients have a history of repeated massive bleeding. After massive upper gastrointestinal bleeding, ascites or complications such as hepatic encephalopathy may occur. In addition, it is not uncommon for advanced schistosomiasis ascites to be complicated with primary peritonitis and Gram-negative bacillary sepsis.

　　2. Intestinal complications
　　The specimens of the excised vermiform appendix of patients in the epidemic area who found schistosome eggs can reach as high as 31%, which is often a cause of acute appendicitis, and the appendix is more prone to rupture, which can lead to peritonitis or localized abscesses.
　　The narrowing of the intestinal lumen caused by severe colonic lesions caused by the disease can lead to incomplete intestinal obstruction, most often located in the sigmoid colon and rectum. In addition, the lesions of the mesentery and omentum can adhere together to form abdominal masses. The granulomas in the colon of patients with the disease can be complicated with colon cancer, with adenocarcinoma being more common in younger patients, with lower malignancy and later metastasis.

　　Most infected individuals with intercalated schistosomiasis may not show obvious symptoms, as the female worms lay eggs in the small venules of the mesentery of the host, and the host's reaction caused by this worm is relatively mild. Liver biopsy may show the formation of eosinophilic abscesses around the eggs; colonoscopy may show congestion of the mucosa near the rectal valves, inflammation of the intestinal wall, or the formation of polyps. Patients may have obvious gastrointestinal symptoms, with blood and mucus in the stool, urgent need to defecate, etc.

　　The prevention and treatment of intercalated schistosomiasis should be carried out according to the specific situation in the epidemic area, adapting to local conditions and time. Measures should focus on the extermination of snails and the treatment of patients and sick animals, combined with comprehensive measures such as fecal and water source management and personal protection.

　　1. Control the source of infection
　　A census is conducted in the epidemic area, and large-scale simultaneous treatment is carried out for patients and sick cattle. The application of praziquantel to expand chemotherapy for controlling schistosomiasis can significantly reduce the number of patients, which is an important link in the entire prevention and control work, especially in lakes and swamp areas and mountainous areas, where there will be significant effects after continuous 3 years. The blood fluke disease in draught cattle can be treated with a suspension of nitrilotriacetic acid 1.5-2mg/kg body weight, with good curative effect after a single intravenous injection.

　　2. Interrupt the transmission route
　　Before controlling snails, it is first necessary to investigate the snail situation, establish a snail situation map, and provide a basis for the control plan. In water network areas, physical snail control methods such as soil burial can be adopted to change the breeding environment of snails; in lakes and marshes, methods such as damming, reclamation, and planting can be adopted; anti-snail belts can be established around residential areas. Chemical snail control can be combined with physical snail control, using snail-killing drugs such as niclosamide, and can be made into slow-release agents to extend the effect of snail control. However, most snail control agents are harmless to crops and animals, but toxic to fish, and water source pollution should be prevented.

　　3. Strengthen personal protection, protect susceptible populations
　　The key is to carry out publicity and education, guide people to pay attention to self-protection, and avoid contact with epidemic water as much as possible in the epidemic area, such as strictly prohibiting children from playing in rivers and ditches. When it is necessary to contact epidemic water in lakes and marshes due to harvesting and fishing, etc., personal protective measures should be taken. For example, a protective agent can be made by adding lauric acid as the matrix, alkali saponification, and then adding 2% niclosamide and turpentine oil. It has the effect of killing the larvae; 1% niclosamide alkaline solution soaked in clothes and pants also has a preventive effect on the larvae.
　　

　　Schistosomiasis intercalata can be diagnosed by finding typical eggs in the stool and rectal mucosa, and the eggs have acid-fast positive reactions. The characteristic of the eggs is that the larvae inside are in the shape of eyeglass glass. Liver biopsy shows that there are eosinophilic abscesses around the eggs; colonoscopy shows that the mucosa near the rectal valves is congested, the intestinal wall is inflamed, or polyps may form.

　　In addition to routine treatment, patients with Schistosomiasis intercalata should also pay attention to the following aspects in diet:

　　1. Suitable diet
　　Eat acid-heavy foods; eat foods that increase intestinal motility; eat foods with vermifuge effects.

　　2. Dietary taboos
　　Avoid eating alkaline foods; avoid eating high-sugar foods; avoid eating greasy foods.

　　Patients with Schistosomiasis intercalata may have obvious gastrointestinal symptoms, such as blood and mucus in the stool, urgent need to defecate, etc. The treatment of Schistosomiasis intercalata with praziquantel is effective, and it can also be treated with niletrazole for 7 days.