Schistosomiasis aegypti
Introduction
Introduction to schistosomiasis in Egypt The schistosomiasis of Egypt was first discovered by Bilhartz in Cairo, Egypt in 1851. To commemorate him, he also called schistosomiasis Bilharziasis. The disease is prevalent in most African countries. According to Egyptian ancient corpse mummies, the disease has been in Africa for thousands of years. Schistosoma japonicum parasitic in the bladder and pelvic venous plexus, producing genitourinary lesions, clinical manifestations of terminal hematuria, bladder irritation and obstruction. basic knowledge The proportion of illness: 0.052% Susceptible people: good for adult men and women Mode of infection: mostly invaded by skin or (and) mucous membranes Complications: acute left heart failure in the elderly
Cause
Causes of schistosomiasis in Egypt
Causes:
The male is 10 to 15 mm long and 0.8 to 1.0 mm wide. The body surface is covered with tiny nodules. The mouth suction cup and the abdominal suction cup are each one. The male body is folded on both sides of the abdominal suction cup to form a female ditch, which has 4 to 5 Testicles, female slender, 20mm × 0.25mm, 20-100 eggs in the uterus, 500-3000 eggs/d, mature eggs are light brown-yellow, the egg shell is transparent, and there is a terminal small spine at the end ( The tail spine is characterized by the presence of active hairs when discharged from the urine and feces.
The intermediate host snails vary from place to place. Africa is a bulbinus, such as B. truncatus, B. globosus, etc., southern India, Mumbai is a narrow iron snail ( Ferrisia tenuis); Portugal, Morocco is the planorbarius metidjensis.
The body of the tail scorpion is round and has five pairs of puncture glands. The scorpion scorpion flows freely in the water after escaping from the snail. It can live for up to 3 days in the water, but most of them die within 24 hours. When the person comes into contact with the infected water, the scorpion Remove the tail, invade the skin by the action of puncture gland secretions. After that, the child worm invades the small vein right heart pulmonary blood vessel liver, develops in the portal vein of the liver, and becomes sexually mature adult, male and female after about 20 days. Insects and blood flow to the inferior mesenteric vein, sometimes staying in the rectal vein, but most adults lay eggs through the iliac vein and the genital vein to the bladder and pelvic venous plexus. A few adults can also lay eggs in the rectum and the inferior mesenteric vein. Invasion from the scorpion to the adult to lay eggs for 10 to 12 weeks.
Pathogenesis:
The pathogen of schistosomiasis in Egypt is mainly caused by egg granuloma. The adult seldom produces lesions. The degree of disease depends on the number of infected insects (worm burden). The schistosomiasis of Egypt is parasitic in the bladder and pelvic venous plexus. Deposition in the bladder and distal ureteral submucosa and muscle layer, especially in the bladder triangle area, the eggs break into the bladder cavity, excreted from the urine, can produce hematuria, but most of the eggs deposited on the bladder wall to produce granulomatous lesions The bladder neck is also a good site for lesions. Under normal circumstances, the muscles in the triangle of the bladder are directly down from the horizontal position, joined to the fine sputum, and become the posterior wall of the urethra. When the muscles in the bladder triangle contract, the urethra shifts backward. The bladder neck is completely open and urinating. If the muscle is damaged by the egg granuloma, causing fibrosis and atrophy, the bladder neck can not be achilled and urinary dysfunction, bladder neck obstruction and bladder wall lesion can cause bladder deformation. , the production of diverticulum, in addition, bladder lesions can produce mucosal hyperplasia, the formation of polyps; finally produce irreversible fibrosis and calcification, ureter or bladder Neck can cause hydronephrosis, secondary bacterial infections, leading to kidney failure.
Reproductive organ lesions, male patients can cause prostate and glans lesions; female patients with the cervix, vagina and labia can also be involved, but less common.
In addition to the genitourinary system, eggs can pass through the inferior mesenteric vein to the appendix, cecum, colon, especially the rectum, and the eggs can be excreted from the feces. A small number of eggs can enter the liver from the portal vein, producing pseudotuberculous nodules and portal veins. Peripheral fibrosis.
Pulmonary lesions, eggs of Schistosoma japonicum can pass through the bladder vein, enter the lungs through the inferior vena cava, and a large number of eggs repeatedly embolize the pulmonary arterioles, producing necrotic occlusive endarteritis, causing pulmonary circulatory obstruction and pulmonary hypertension, according to Egyptian autopsy As a result, about 30% of patients had pulmonary artery disease. In the proximal part of the pulmonary circulatory occlusion, due to the damage of the middle vascular layer and pulmonary hypertension, the pulmonary artery often showed angioidoid expansion. Because the obstruction site was not in the microvessel or alveoli before the pulmonary microvessel, it did not cause a deficiency. Oxygen or cyanosis, not accompanied by myocardial damage.
Prevention
Egyptian schistosomiasis prevention
According to the specific conditions of the epidemic areas, the following measures should be taken according to local conditions and appropriate measures.
1. Flies control: In Africa, measures to combine water conservancy construction with the use of snail control drugs, the intermediate host density of snails in the dry season in the rivers, greatly reduced, but there are still snails lurking in the soil voids or shades to survive, After the dry season, it will reproduce and multiply and become a medium of communication. Therefore, the work of killing snails must be repeated.
2. Large-scale treatment: In Egypt, chemotherapy (praziquantel) has been used for a large number of people. It has not been successful in eradicating this disease, mainly because it cannot prevent reinfection, and it is treated with praziquantel 40 mg/kg body weight. One dose of therapy, oral, has the advantages of good curative effect and less side effects, and is effective for social control of this disease.
3. Improve environmental sanitation: For manure management, safe water prevents human-spiral infections, is difficult to do, and is expensive.
Complication
Egyptian schistosomiasis complications Complications, acute left heart failure in the elderly
Male patients can cause prostate and glans lesions; female patients with cervix, vagina and labia can also be involved, but less common, pseudotuberculous nodules and fibrosis around the portal vein, lung lesions, and late right heart failure.
Symptom
Symptoms of schistosomiasis in Egypt Common symptoms Abdominal pain Urinary urinary tract obstruction Diarrhea Urinary pain Retrograde bacterial infection Weakness
The incubation period from the cercaria to the urine appears in the eggs for 10 to 12 weeks.
1. The acute phase is in the epidemic area of the disease, most of the patients are repeated infections, so the acute phase symptoms are rare. Only a few patients have fever, headache, fatigue and other systemic symptoms, common urticaria, abdominal pain and liver, splenomegaly, blood The number of eosinophils was significantly increased, and the clinical manifestations were similar to those of acute Japanese schistosomiasis, but were milder.
2. Early symptoms in the chronic phase are painless terminal hematuria, which can last for several months or years without other symptoms, but gradually appear urinary frequency, dysuria and other symptoms of chronic bladder inflammation, which in turn leads to dysuria, urinary tract obstruction. Hydronephrosis, retrograde bacterial infection, and finally kidney failure.
Cystoscopy revealed sandy patches of massive granuloma on the bladder wall, mucosal proliferative inflammation and papillary growth, and stones composed of uric acid, oxalic acid and phosphate, in Egypt, 83.1% bladder Cancer patients have schistosomiasis lesions, so schistosomiasis in Egypt may induce cancer. These patients are younger, around 40 years old, mostly fully differentiated squamous cell carcinoma; metastasis is rare, and appears later.
(1) Liver and intestine symptoms: far less than Japanese schistosomiasis, lighter, later, mainly caused by egg granuloma around the colon and hepatic portal vein, excretion of eggs from the feces of patients with diarrhea and dysentery, hepatosplenomegaly and liver Symptoms such as fibrosis are generally mild.
(2) Pulmonary symptoms: less common, patients complain of fatigue, dizziness, headache, palpitations, pain in the anterior region, about 1/3 of patients with coma after exertion, chest X-ray showed significant expansion of the pulmonary artery, ECG visible P wave towering With right ventricular hypertrophy, right heart failure can be complicated in the late stage. Because the disease is obstructive pulmonary heart disease and no myocardial injury, it occurs later. According to the Egyptian report, only 0.8% to 1% of patients in the clinic cause pulmonary heart disease and schistosomiasis. Pulmonary heart disease accounts for only 4% of the total number of heart disease patients.
(3) Reproductive system symptoms: male patients with prostate can be caused by inflammation of the egg deposits, the quality becomes hard, sometimes a large number of eggs can be found from the semen, and the eggs reach the spermatic vein through the mesenteric vein anastomosis, which can cause spermatic cord and epididymal lesions. Due to the fibrosis of the scrotum, the scrotal lymphatics are obstructed, and the reflux is not smooth, which can cause the genital swelling of the penis turtle. The reproductive system symptoms of female patients are less obvious. There may be cervical, vaginal and labial lesions, and fallopian tubes and hysteritis are rare.
Examine
Examination of schistosomiasis in Egypt
The eosinophils in the blood are significantly increased. The eggs of the tail thorns are found in the urine. After the last few drops of hematuria, the smear can be found by direct smear and the urine sediments are incubated. The mites can be seen from 10 minutes to 2 hours.
A biopsy was taken directly from the cystoscope, and a large number of eggs were observed by the tableting method.
Diagnosis
Diagnosis and identification of schistosomiasis in Egypt
Patients with painless terminal hematuria in the epidemic area of this disease should be suspected to be schistosomiasis in Egypt. The diagnosis depends on the eggs found in the urine from the tail. The last few drops of hematuria can be found by direct smear after centrifugation. The urine sediment can be hatched. After 10 minutes to 2 hours, the edulis can be seen. The biopsy is taken directly from the cystoscope. A large number of eggs can be found by the tableting method. Most of the eggs are excreted from the urine, but there are also calcified eggs. Rectal mucosal biopsy can sometimes find eggs. Immunological tests have a cross-reactivity with schistosomiasis due to the specificity of the applied antigen. The two cannot be identified, but have early diagnostic value for the acute phase.
The clinical symptoms of schistosomiasis in Egypt are complex and mainly need to be differentiated from urinary system diseases such as kidney stones, nephritis, kidney tuberculosis, bladder cancer and cystitis.
