Shekhar K C
Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur.
Singapore Med J. 1994 Dec;35(6):616-21.
S. mansoni and S. japonicum complex schistosomes cause hepatosplenic and hepatointestinal schistosomiasis. The prevalence and incidence of this disease is increasing in all the endemic areas. Hepatosplenic schistosomiasis is seen in a small subset of clinically infected patients and represents a good model of intrahepatic portal hypertension characterised by a presinusoidal portal block and a well preserved liver parenchyma. Symmers' fibrosis is seen in a significant proportion of patients with high worm load. While the pathogenesis of Symmers' pipe stem fibrosis has not been well established, experimental and clinical data point to egg induced granulomata. The main consequences are presinusoidal portal hypertension, oesophageal varices and hepatosplenomegaly. The most striking symptoms are haematemesis or melena secondary to variceal and gastrointestinal bleeding. Cofactors associated with the pathogenesis include aflatoxins, malnutrition, alcoholism, hepatitis B and C virus. While stool examination is the best technique for diagnosis, a number of immunological tests though sensitive are not specific. Ultrasonography is sensitive for detection of Symmer's fibrosis. Praziquantel and oxaminiquine are drugs found to be effective in the treatment of hepatosplenic schistosomiasis. Recently beta-blockers have been found to be effective in the treatment of gastrointestinal rebleeding. Endoscopic sclerotherapy has been found to be effective for treatment of bleeding oesophageal varices. The treatment of choice for portal hypertension is oesophagogastric devascularization with splenectomy (EGDS).
曼氏血吸虫和日本血吸虫复合种可导致肝脾型和肝肠型血吸虫病。在所有流行地区,这种疾病的患病率和发病率都在上升。肝脾型血吸虫病见于一小部分临床感染患者,是肝内门静脉高压的一个良好模型,其特征为窦性前门静脉阻塞和肝实质保存良好。在大量虫负荷的患者中,可观察到席默氏纤维化。虽然席默氏干线性纤维化的发病机制尚未完全明确,但实验和临床数据表明是虫卵诱发的肉芽肿所致。主要后果是窦性前门静脉高压、食管静脉曲张和肝脾肿大。最显著的症状是静脉曲张和胃肠道出血继发的呕血或黑便。与发病机制相关的辅助因素包括黄曲霉毒素、营养不良、酗酒、乙型和丙型肝炎病毒。虽然粪便检查是最佳诊断技术,但一些免疫学检测虽然敏感但不具有特异性。超声检查对席默氏纤维化的检测很敏感。吡喹酮和奥沙米喹被发现对肝脾型血吸虫病有效。最近发现β受体阻滞剂对胃肠道再出血有效。内镜硬化疗法已被发现对治疗食管静脉曲张出血有效。门静脉高压的首选治疗方法是食管胃去血管化加脾切除术(EGDS)。