Interstitial schistosomiasis
Introduction
Introduction to interstitial schistosomiasis Interstitial schistosomiasis is an endemic parasitic disease caused by parasitic schistosome intercalatum parasitic in the intestinal tract. basic knowledge The proportion of illness: 0.0002% Susceptible people: no special people Mode of infection: digestive tract spread Complications: liver fibrosis hemorrhagic shock ascites hepatic encephalopathy cirrhosis peritonitis sepsis acute appendicitis abscess intestinal obstruction colon cancer
Cause
Intercalation of schistosomiasis
(1) Causes of the disease
The size of the adult insect varies with the host and is easily confused with other species of schistosomiasis. The male is 11.5 to 14.5 mm long and 0.3 to 0.5 mm wide. The testicles are 2 to 7, mostly 4, with ventral, lateral and dorsal spines. From the back of the testicle, the epidermis has small nodules. The females are 13 to 24 mm long and 0.2 to 0.25 mm wide. The ovaries are located between the intestines and are mostly spirally twisted. The average number of eggs in the uterus is 140 m × 37 m, about 25%. ~60% of the worms began to lay eggs 80 days after infection, and the maximum number of eggs per worm was 122. The ends of the eggs had spines, microbends, and the eggshells were positive for acid-fast staining. They were fixed with Bouin solution, and the middle of the ridges contained the blister The characteristics of schistosomiasis are: 1) the tissue sputum is positive for the egg-negative staining; the 2 scorpion is the surface of the sputum or near the surface of the water; the scorpion has a tendency to attach foreign objects; 5; at most of the propagation points only intervening schistosomiasis, only a few places with the Schistosoma sinensis, only in Cameroon with the Egyptian schistosomiasis.
(two) pathogenesis
The pathogenesis is basically the same as that of Schistosoma japonicum and Schistosoma mansoni.
The characteristics of schistosomiasis are:
1 In the tissue section, the egg-negative staining reaction was positive;
2 hi gathers the water surface or near the water surface;
3 tails have a tendency to attach foreign objects;
The glandular secretions of the 4 cercariae are in a granular line;
5 In most of the transmission points, only interspersed with schistosomiasis, only a few places with the Schistosoma sinensis, only in Cameroon and the Egyptian schistosomiasis.
Prevention
Interstitial schistosomiasis prevention
prevention
Actively treat infected people and animals. Carry out general census in popular areas; use chlorhexidine and other snails to remove the environment that is easy to breed snails; properly handle the excrement of patients and animals to avoid polluting water sources; personal protection should avoid contact with infected water. It is difficult to avoid wearing long-term rubber boots when contact with infected water. For those who have contact with infected water, they should take preventive drugs such as artesunate.
According to the specific conditions of the epidemic areas, prevention and control should be carried out according to local conditions, and comprehensive measures combining manure and water source management and personal protection should be adopted to focus on the elimination of snails and general treatment of sick animals.
1. Control the source of infection in the popular area for census, large-scale simultaneous treatment of patients and diseased cattle, the use of praziquantel to expand chemotherapy to control the schistosomiasis epidemic, the number of patients can be greatly reduced, which is important in the overall prevention and treatment work A ring, especially in the lakes and mountains and mountains, will have significant results after three consecutive years. The schistosomiasis of cattle can be 1.5~2 mg/kg body weight of nitric thiocyanate suspension, and one intravenous injection has good curative effect.
2. Before cutting off the transmission route, the snail condition should be firstly clarified, and the snail map should be established. In order to provide the basis for the snail-killing plan, the physical snails such as soil burial method that change the environment of snail snails can be taken in the water network area. The area can be built with dams, cofferdams, and planting methods. Anti-snails can be built around the residential sites. Chemical snails can be combined with physical snails, and snail-killing drugs such as niclosamide can be used. Extend the effect of snail killing, but most of the snail-killing agents are harmless to crops and humans, but they are poisonous to fish and should be protected from water pollution.
Manure management: prevent human feces and livestock manure from polluting the water source, and treat it to make it harmless. For example, it should be sealed after mixing 1:5 of feces and urine, precipitated and fermented, stored in summer for 3 to 5 days, and in winter for 7 to 10 days, it can be killed. Dead blood trematode eggs, in addition, the use of biogas septic tanks in rural areas should be vigorously promoted.
Water source management: Protect the water source from pollution, promote clean water, or store the river water for 3 days. If necessary, use chlorine-containing lime, add 1g per water (about 50kg), and use it after disinfection for 15 minutes.
3. Strengthen personal protection and protect susceptible people
(1) The key lies in propaganda and education, guiding people to pay attention to self-protection, and avoiding contact with infected water in popular areas. For example, children are strictly prohibited from playing in the river ditch. When harvesting and harvesting in lakes and lakes, lakes and grasses must be exposed to infected water. Take personal protective measures, use fatty acid as matrix, add alkali to saponification, add niclosamide (2%) and turpentine to make protective agent, kill cercaria, 1% niclosamide alkaline solution impregnated underwear It also has a preventive effect on the cercaria.
(2) Preventive medication: Artemisin derivatives artemether and artesunate can kill schistosomiasis worms for 5 to 21 days. Artemisin ether usage: 15 days after exposure to infected water Take 1 artemether (6mg/kg each time), 1 time / 15 days, and then take 4 to 10 times. Artesunate usage: Take artesunate once every 7 days after exposure to the water. 6mg/kg), 1 time/week, and even 8 to 15 times, can effectively prevent schistosomiasis infection. According to 1996-1998, it has promoted the application of artesunate in Jiangxi, Anhui and Hubei provinces. The protection rate of 10,000 people is 88.2%-100%; artemether has also been applied in more than 2,000 people (1994-1996) in the above-mentioned areas, and its protection rate is also 60%-100%.
Complication
Intervening schistosomiasis complications Complications liver fibrosis hemorrhagic shock ascites hepatic encephalopathy cirrhosis peritonitis sepsis acute appendicitis abscess intestinal obstruction colon cancer
1. Liver fibrosis complications in patients with advanced schistosomiasis complicated by lower esophageal or gastric varices accounted for more than 2 / 3, varicose veins caused by upper gastrointestinal bleeding accounted for 16.5% ~ 31.6%, is the main cause of schistosomiasis fibrosis Complications, clinical symptoms are a large number of hematemesis and black feces, can cause blood pressure drop and hemorrhagic shock, the mortality rate is about 15%, about half of the patients have repeated hemorrhage history, ascites or hepatobiliary can occur after massive hemorrhage of the upper digestive tract Encephalopathy, hepatic encephalopathy in the late stage schistosomiasis is less than portal vein and cirrhosis after necrosis, domestic reports accounted for 1.6% to 5.4%, and its course of disease is also longer, in addition, advanced schistosomiasis ascites complicated by primary peritonitis and leather It is not uncommon for gram-negative bacilli to be septic.
2. In patients with intestinal complications, the schistosomiasis in the resected appendix specimens can be as high as 31%, which is often a cause of acute appendicitis, and the appendix is easy to wear, and can be complicated by peritonitis or localized abscess.
Intestinal stenosis caused by schistosomiasis caused by severe colonic lesions may be complicated by incomplete intestinal obstruction, which is located in the sigmoid colon and rectum. In addition, mesenteric and omental lesions may adhere to a mass, forming an intra-abdominal mass, schistosomiasis Colonic granuloma can be complicated by colon cancer. The patients are younger, mostly adenocarcinoma, with a lower degree of malignancy and a later metastasis.
Symptom
Symptoms of intervening schistosomiasis Common symptoms Inflammatory mucosal congestion, acute polyp abscess
Most patients may have no obvious symptoms after infection. In severe cases, there may be sudden pain in the left tibia. Because the female lays eggs in the mesenteric venules of the host, the host response caused by the worm is lighter. Liver biopsy shows that there are around the eggs. Eosinophilic abscess formation, colonoscopy can be seen near the rectal flap mucosal congestion, intestinal wall inflammation or polyps formation, patients may have obvious gastrointestinal symptoms, blood and mucus in the stool, and then urgency.
Examine
Interstitial schistosomiasis
A typical egg can be found in the stool and rectal mucosa to confirm the diagnosis. The eggs are positive for acid-fast staining, and the hairs in the eggs are characterized by glasses and glasses.
Liver biopsy showed the formation of eosinophilic abscess around the eggs. Colonoscopy showed mucosal congestion near the rectal flap, inflammation of the intestinal wall or formation of polyps. Patients may have obvious gastrointestinal symptoms, blood and mucus in the stool, and urgency.
Diagnosis
Diagnosis and identification of interstitial schistosomiasis
Diagnostic criteria
1. Epidemiological data include the history of travel in epidemic areas in western China, Zaire, Cameroon, Gabon and other countries.
2. Clinical manifestations may have sudden pain in the left axillary fossa, may have gastrointestinal symptoms, stool has mucus or blood and a history of urgency and weight.
3. Laboratory examination can be confirmed by finding typical eggs in the stool and rectal mucosa. The eggs are positive for acid-fast staining, and the hairs in the eggs are characterized by glasses and glasses.
Differential diagnosis
Acute schistosomiasis is misdiagnosed as typhoid fever, amoebic liver abscess, miliary tuberculosis, etc., and significant increase in eosinophils in blood has important differential diagnostic value. It cannot be ignored. Chronic schistosomiasis liver splenomegaly should be associated with no jaundice virus. Identification of sexual hepatitis, the latter's loss of appetite, fatigue, liver pain and liver function impairment are more obvious, acute and a few patients with chronic schistosomiasis may have false positive HBsAg (RPHA method), and related to heterophilic antibodies, so serum should be checked at the same time Other hepatitis B signs or not using RPHA method, schistosomiasis patients have diarrhea, blood in the feces of stools are positive, and the number of hairy mites is more, easy to distinguish from amoebic dysentery, chronic dysentery, advanced schistosomiasis and portal vein And the identification of liver cirrhosis after necrosis: the former often has chronic diarrhea and blood history, portal vein hypertension caused by splenomegaly and lower esophageal varices are more common, liver function damage is lighter, jaundice, spider mites and liver palm are less common, but still need It can be identified by relying on multiple pathogens and immunological tests. It should be noted that schistosomiasis with hepatitis B in the endemic area is more common in China. See, in addition, in patients with epilepsy in endemic areas should be possible except brain schistosomiasis.
