Pathogenesis
1 致病因子
(1)虫株毒力 RH株(强毒株) Beverley株 (弱毒株)
(2)机体免疫状态 (属Opportunistic protozoiasis)
2 致病机制
(1)tachyzoites 导致组织急性炎症和坏死
(2)bradyzoites 是慢性感染的主要形式,cyst挤压器官组织,破裂后刺激机体发生变态反应,形成肉芽肿,纤维化。
3 临床分类
(1)先天性弓形虫病
发生于初孕妇女,经胎盘感染胎儿,可致流产、早产、畸胎或死产。怀孕早期感染畸胎发生率高。
主要累及大脑和眼,如脑积水、脑钙化、视网膜脉络膜炎和精神、动物障碍为典型症候。
Hydrocephalitis
intracraninal calcification
Chorioretinitis
(2)获得性弓形虫病(多为隐性感染,属机会致病原虫,AIDS等病时转为急性重症,恶化)(1) 淋巴结肿大 患者淋巴结肿大,变硬,有橡皮样感,伴有长时间低热,疲倦,肌肉不适等。
(3) 眼病,较先天性弓形虫病少见,有些不先天性感染但到成年后发作所致。
Photograph of fundus. Showing a heavily pigmented central choroidal lesion in a young person due to acquired toxoplasmosis. The whitish patches inside the lesion are areas where the sclera is exposed due to the necrosis of the retina. A sharply demarcated lesion, as seen in this photograph, is typical of both acquired and congenital toxoplasmosis. However, in some cases a more diffused lesion may be observed.